AS/NZS 1715:1994

Australian/New Zealand Standard

Selection, use and maintenance ofrespiratory protective devices

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AS/NZS 1715:1994

This Joint Australian/New Zealand Standard was prepared by Joint TechnicalCommittee SF/10, Industrial Respiratory Protection. It was approved on behalf of theCouncil of Standards Australia on 17 March 1994 and on behalf of the Council ofStandards New Zealand on 27 April 1994. It was published on 16 May 1994.

The following interests are represented on Committee SF/10:

Australian Assembly of Fire AuthoritiesAustralian Institute of PetroleumComposites Institute of AustraliaConfederation of Australian IndustryCounty Fire Authority, AustraliaDepartment of Defence, AustraliaDepartment of Labour, VictoriaDepartment of Minerals and Energy, N.S.W.Electricity Supply Association of AustraliaGas Fuel Corporation, VictoriaMetal Trades Industry Association, AustraliaSafety Institute of AustraliaWater Board, Sydney—Illawarra—Blue MountainsWorkCover Authority of N.S.W.

Review of Standards. To keep abreast of progress in industry, Joint Australian/NewZealand Standards are subject to periodic review and are kept up to date by the issueof amendments or new editions as necessary. It is important therefore that Standardsusers ensure that they are in possession of the latest edition, and any amendmentsthereto.Full details of all Joint Standards and related publications will be found in theStandards Australia and Standards New Zealand Catalogue of Publications; thisinformation is supplemented each month by the magazines ‘The Australian Standard’and ‘Standards New Zealand’, which subscribing members receive, and which givedetails of new publications, new editions and amendments, and of withdrawnStandards.Suggestions for improvements to Joint Standards, addressed to the head office of eitherStandards Australia or Standards New Zealand, are welcomed. Notification of anyinaccuracy or ambiguity found in a Joint Australian/New Zealand Standard should bemade without delay in order that the matter may be investigated and appropriate actiontaken.A

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AS/NZS 1715:1994

Australian/New Zealand Standard

Select ion , us e and maintenanc e ofresp irator y protect ive devices

For history before 1994 see Preface.

Jointl y revised and designated as Joint StandardAS/NZS 1715:1994.

PUBLISHED JOINTLY BY:

STANDARDS AUSTRALIA1 The Crescent,Homebush NSW 2140 Australia

STANDARDS NEW ZEALANDLevel 10, Radio New Zealand House,155 The Terrace,Wellington 6001 New Zealand

ISBN 0 7262 8878 0

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AS/NZS 1715:1994 2

PREFACE

This Standard was prepared by the Joint Australia/New Zealand Standards CommitteeSF/10 on Industrial Respiratory Protection to supersede AS 1715—1991.

This Standard is issued as a Joint Standard under the terms of the Active CooperativeAgreement between Standards Australia and Standards New Zealand.

This Standard was revised in 1994 with the objective of taking account of the changes toAS/NZS 1716:1994,Respiratory protective devices, and problems of interpretations thathave arisen since AS 1715 was last published in 1991.

As most readers will not need to refer to the performance and testing specificationAS/NZS 1716:1994, the listings of definitions and referenced Standards have beenexpanded to include several new definitions and Standards to aid the reader’sunderstanding of the text.

The list of regulatory authorities has been revised.

Throughout the text, examples of types of chemicals or other technical concepts have beenexpanded. Additional warnings about the possible misuse of respirators have also beenincluded. Qualitative facial fit testing has been retained as being a suitable means ofmonitoring a respirator program.

It has been the aim of the Committee to further explain that the provision of a respiratoris only part of ensuring an overall system of respiratory protection for all employees.

The history of the Standards which have been revised and amalgamated to form thisStandard is as follows:

In Australia, AS CZ11 was first published in 1960 and revised in 1968. This Standard wasrevised and redesignated AS 1715 in 1975, with a second edition in 1982 and a thirdedition in 1991.

In New Zealand the Standard was first published in 1961 in part as NZS 1586, being anendorsement of BS 2091:1954 with amendments. NZS 1586 was superseded in part byNZS 2267 in 1969. NZS 2267 was replaced in part by NZS/AS 1715-1991 (harmonized)in 1992.

Requirements for the performance and testing of respiratory protective devices are notcovered in this Standard but are specified in AS/NZS 1716:1994.

Additional relevant Standards which may assist with the selection, care and use ofrespiratory devices have been specified under the heading of Related Documents(Clause 1.4).

The terms ‘normative’ and ‘informative’ have been used in this Standard to define theapplication of the appendix to which they apply. A ‘normative’ appendix is an integralpart of a Standard, whereas an ‘informative’ appendix is only for information andguidance.

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3 AS/NZS 1715:1994

CONTENTS

Page

SECTION 1 SCOPE AND GENERAL1.1 SCOPE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51.2 GENERAL PRINCIPLES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51.3 REFERENCED DOCUMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51.4 RELATED DOCUMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61.5 DEFINITIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

SECTION 2 ENTRY OF SUBSTANCES INTO THE BODY2.1 GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112.2 INHALATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112.3 ABSORPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142.4 INGESTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

SECTION 3 OXYGEN-DEFICIENT ATMOSPHERES3.1 GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163.2 ATMOSPHERIC COMPOSITION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163.3 SYMPTOMS OF OXYGEN DEFICIENCY . . . . . . . . . . . . . . . . . . . . . . . . . 17

SECTION 4 HAZARD RECOGNITION, EVALUATION AND CONTROL4.1 RECOGNITION OF HAZARDS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 184.2 HAZARD EVALUATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 184.3 HAZARD CONTROL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

SECTION 5 TYPES OF RESPIRATOR5.1 METHOD OF PROVIDING PERSONAL RESPIRATORY PROTECTION . . 205.2 TYPES OF RESPIRATOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205.3 AIR-PURIFYING RESPIRATORS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205.4 SUPPLIED AIR RESPIRATORS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

SECTION 6 SELECTION OF RESPIRATORS6.1 FACTORS IN SELECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 276.2 SELECTION FACTORS—CONTAMINANT-RELATED . . . . . . . . . . . . . . . 286.3 SELECTION FACTORS—TASK-RELATED . . . . . . . . . . . . . . . . . . . . . . . 376.4 SELECTION FACTORS—OPERATOR-RELATED . . . . . . . . . . . . . . . . . . . 39

SECTION 7 THE RESPIRATORY PROTECTION PROGRAM7.1 MANAGEMENT RESPONSIBILITY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 417.2 COMPLIANCE OF EQUIPMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 417.3 MEDICAL SCREENING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 427.4 ISSUE OF RESPIRATORS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 437.5 FACIAL FIT TESTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 437.6 CLEANING AND MAINTENANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 447.7 INSPECTION FOR DEFECTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 467.8 INSPECTION AND MAINTENANCE CONSIDERATIONS . . . . . . . . . . . . 467.9 SAFE WORKING PRACTICES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

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7.10 REPLACEMENT OF FILTERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 507.11 ENSURING THE CONTINUED EFFECTIVENESS OF

THE RESPIRATOR PROGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 517.12 TRAINING IN RESPIRATORY PROTECTION USAGE . . . . . . . . . . . . . . . 51

SECTION 8 SPECIFIC MAINTENANCE REQUIREMENTS8.1 SERVICING FACEPIECES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 528.2 SERVICING EXHALATION VALVES . . . . . . . . . . . . . . . . . . . . . . . . . . . 528.3 SERVICING OTHER COMPONENT PARTS . . . . . . . . . . . . . . . . . . . . . . . 52

APPENDICESA REQUIREMENTS FOR AIR QUALITY (COMPRESSORS OR CYLINDERS)

FOR SUPPLIED AIR RESPIRATORS . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53B ADVISORY AUTHORITIES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55C RESPIRATOR SELECTION EXAMPLES . . . . . . . . . . . . . . . . . . . . . . . . . 57D TYPICAL RESPIRATOR FIT TESTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59E FACIAL SEAL OF RESPIRATORS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64F EMPLOYEE TRAINING PROGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66G TYPICAL METHOD OF MEASURING VALVE LEAKAGE . . . . . . . . . . . . 71H COMPRESSED BREATHING AIR FILTRATION SYSTEMS . . . . . . . . . . . 73I TYPICAL METHOD OF MEASURING INHALATION AND

EXHALATION RESISTANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75J CHECKPOINTS FOR RESPIRATOR PROGRAM ADMINISTRATION AND

OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77

INDEX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79

Copyright STANDARDS AUSTRALIA/ STANDARDS NEW ZEALAND

Users of Standards are reminded that copyright subsists in all Standards Australia and Standards New Zealand publications and software.Except where the Copyright Act allows and except where provided for below no publications or software produced byStandards Australia or Standards New Zealand may be reproduced, stored in a retrieval system in any form or transmitted by any meanswithout prior permission in writing from Standards Australia or Standards New Zealand. Permission may be conditional on an appropriateroyalty payment. Australian requests for permission and information on commercial software royalties should be directed to the headoffice of Standards Australia. New Zealand requests should be directed to Standards New Zealand.

Up to 10 percent of the technical content pages of a Standard may be copied for use exclusively in-house by purchasers of theStandard without payment of a royalty or advice to Standards Australia or Standards New Zealand.

Inclusion of copyright material in computer software programs is also permitted without royalty payment provided such programsare used exclusively in-house by the creators of the programs.

Care should be taken to ensure that material used is from the current edition of the Standard and that it is updated whenever the Standardis amended or revised. The number and date of the Standard should therefore be clearly identified.

The use of material in print form or in computer software programs to be used commercially, with or without payment, or in commercialcontracts is subject to the payment of a royalty. This policy may be varied by Standards Australia or Standards New Zealand at any time.

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STANDARDS AUSTRALIA /STANDARDS NEW ZEALAND

Australian/New Zealand Standard

Selection, use and maintenance ofrespiratory protective devices

S E C T I O N 1 S C O P E A N D G E N E R A L

1.1 SCOPE This Standard sets out the principles of respiratory protection and makesrecommendations for the selection, use and maintenance of personal respiratory protectivedevices (respirators) for the protection of the body against atmospheres deficient inoxygen or against harmful substances which could enter the body through the respiratorysystem, or both. Harmful substances may be in the form of dusts, mists, fumes, smokes,gases and vapours, or combinations of these substances.

This Standard does not deal with the special problems connected with diving andunderwater breathing (see AS 2299), the use of respirators in aircraft, or the use of lifesupport respirators for medical or resuscitation purposes.

Design, manufacturing and type approval test requirements for respiratory protectivedevices are not covered in this Standard, but are specified in AS/NZS 1716.

1.2 GENERAL PRINCIPLES The following principles should be observed in theprotection of the body against the effects of harmful substances:

(a) No person should be exposed without suitable protection to an atmosphere that is ormay be injurious to health.

There are substances which are irritant to or which can be absorbed through theskin. Where an atmosphere containing such substances is to be entered,respiratory protection alone is not sufficient and appropriate protective equipmentand clothing should be used.

(b) Where the workplace atmosphere is or may become contaminated, a regular system oftesting by a properly trained and responsible person using suitable equipment shouldbe undertaken.

(c) Every effort should be made to prevent the release of harmful substances into theworking environment. This may be achieved through the design of buildings, plantand equipment; or by work procedures and controls (e.g. extraction systems) toobviate the need for respirators.

(d) If efforts to prevent or control the hazard at the source are unsuccessful, suitablerespirators should be provided and used.

(e) In emergencies where contaminants may be released into the atmosphere, suitablerespirators should be provided and worn.

1.3 REFERENCED DOCUMENTS The following documents are referred to in thisStandard:

AS1020 The control of undesirable static electricity

1210 Unfired Pressure Vessels (known as the SAA Unfired Pressure Vessels Code)

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AS1319 Safety signs for the occupational environment

1345 Identification of the contents of piping, conduits and ducts

2030 The approval, filling, inspection, testing and maintenance of cylinders for thestorage and transport of compressed gases (known as the SAA Gas CylindersCode)

2030.1 Part 1: Cylinders for compressed gases other than acetylene

2299 Occupational diving

2337 Gas cylinder test stations

2337.1 Part 1: General requirements, inspections and tests—Gas cylinders

2380 Electrical equipment for explosive atmospheres—Explosion-protectiontechniques

2380.2 Flame proof enclosure d2380.7 Intrinsic safety i

2865 Safe working in a confined space

2985 Workplace atmospheres—Method for sampling and gravimetric determinationof respirable dust

3765 Clothing for protection against hazardous chemicals3765.1 Part 1: Protection against general or specific chemicals3765.2 Part 2: Limited protection against specific chemicals

SAAMP69 Explosion-protected electrical equipment—Certification scheme—Policy

AS/NZS1716 Respiratory protective devices

ISOTR 7708 Air quality—Particle size fraction definitions for health-related sampling

NOHSC* Exposure standards for atmospheric contaminants in the occupationalenvironment (first published May 1990)

1.4 RELATED DOCUMENTS The following documents are specified as references toassist with the selection, care and use of respiratory devices:

AS1470 Health and safety at work—Principles and practices

2986 Workplace atmospheres—Organic vapours—Sampling by solid adsorptiontechniques

3640 Workplace atmospheres—Method for sampling and gravimetric determinationof inspirable dust

1.5 DEFINITIONS For the purpose of this Standard, the definitions below apply.

1.5.1 Acute—health effects of rapid onset.

1.5.2 Air-hose respirator—a device, used with a facepiece or headcovering, throughwhich respirable air from a source remote from the workplace is made available to thewearer through an air hose at near atmospheric pressure.

* National Occupational Health and Safety Commission

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1.5.3 Air-line respirator —a device through which air, at greater than atmosphericpressure, from a source of compressed air capable of providing breathing air of the qualitydefined in Appendix A, is supplied to the wearer by means of an air-line.

1.5.4 Air-purifying respirator —a device which filters contaminants from inhaled air.

1.5.5 Atmospheric contaminant—any substance, either gaseous or particulate, which isnot a constituent of the normal atmosphere or which is present in a concentration greaterthan that found in the normal atmosphere.

1.5.6 Breathing air—see respirable air.

1.5.7 Chronic—health effects which may have a slow onset and are long lasting.

1.5.8 Combination filter respirator —a device combining the filtration capabilities ofgas and particulate filters. The filters may be a single unit (integral) or consist of separatefilters in series to form one unit (combination).

1.5.9 Demand valve—a device for the controlled release of air or oxygen actuated by areduction in pressure created by the action of inhalation. The regulation may be such thatthe pressure inside the facepiece is maintained above atmospheric pressure (positivepressure type) or falls to below atmospheric pressure (negative pressure type) during theinhalation phase.

1.5.10 Disposable respirator—a device for which maintenance is not intended andwhich is designed to be discarded after excessive resistance, sorbent exhaustion, physicaldamage or end of service-life renders it unsuitable for use.

1.5.11 Dust—solid particles suspended in the air as a result of the disintegration ofmatter. Dust may be generated by mechanical means.

1.5.12 Escape type respirator—a device for emergency escape from a respiratoryhazard.

1.5.13 Facial fit check—a quick check to ensure that the respirator is fitting each timeit is donned, e.g. positive and negative pressure fit checks.

1.5.14 Facial fit test—a validated method of matching a specific respirator to anindividual.

1.5.15 Filter—a component of air-purifying respirators through which inhaled air passesand which removes particulates or certain gases or both. Filters may form part of theconstruction of the facepiece, may be attached to the facepiece or may be carriedseparately and connected to the facepiece by a breathing hose.

1.5.16 Filtration type escape respirator—a device incorporating filters which removescertain particulates and gases or vapours from the air inhaled by the wearer for a limitedtime during escape from a respiratory hazard.

1.5.17 Full facepiece—a close fitting device to cover the eyes, nose and mouth and besecured in position by suitable means.

1.5.18 Fume—particles forming an airborne suspension. Fuming is usually caused bythe heating of a solid to such an extent that it vaporizes and then condenses into smallparticles in the surrounding air. Fume may be termed a thermally generated particulate.

NOTE: Within the context of this Standard the term fume does not include vapours, gases or acombination of these.

1.5.19 Gas—a substance which is airlike. It is neither solid nor liquid at roomtemperature. The term gas in this Standard also includes vapours.

1.5.20 Gas filter—a filter designed to remove certain substances in gaseous or vapourform from the inhaled air.

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1.5.21 Gas filter respirator—a device consisting of a half facepiece, full facepiece orhead covering or mouthpiece with a filter which removes certain gases or vapours fromthe air to be inhaled by the wearer for a limited time. It may also incorporate a filter toremove particulates.

1.5.22 Half facepiece—a close fitting device to cover the nose, mouth and chin and besecured in position by suitable means.

1.5.23 Head covering—a hood, blouse or helmet covering all or most of the head andextending where appropriate to the shoulders or waist. It may include sleeves and issecured in position by suitable means.

1.5.24 Hose-mask respirator—a respirator, used with a full facepiece through whichrespirable air from a source remote from the workplace is available to the wearer throughan air hose at atmospheric or near atmospheric pressure.

1.5.25 Immediately dangerous to life and health (IDLH)—exposure to an atmospherethat poses an immediate adverse effect on health or the ability to escape.

1.5.26 Informative—describes material which doesnot form an integral part of theStandard but provides additional information and, for reasons of convenience, is placedafter the body of the Standard.

NOTE: An informative appendix doesnot contain conditions that are mandatory.

1.5.27 Inspirable fraction—those airborne particles which are taken through the nose ormouth during breathing and which have been so defined by the International StandardsOrganization in ISO/TR 7708.

1.5.28 Local effects—reactions by parts of the body in contact with a contaminant.

1.5.29 Mechanically generated particulates—seedust and mist.

1.5.30 Mist—airborne droplets. The droplets may carry substances in solution orparticles in suspension. Mists are usually formed by the condensation of vapour but maybe produced by the atomization of a liquid (seedust).

1.5.31 Mouthpiece—a device, designed to be held in the mouth, through which allbreathing air passes. Normally used in conjunction with a nose clip.

1.5.32 Natural breathing—the normal breathing action of the wearer draws air into thefacepiece through filters or wide bore tube. The pressure inside the respirator is at or nearatmospheric pressure.

1.5.33 Normative—describes material which is an integral part of the body of theStandard and, for reasons of convenience, is placed after the body of the Standard.

NOTE: All requirements set out in a normative appendix must be met for compliance with thisStandard.

1.5.34 Nose clip—a device designed to occlude the nostrils to prevent air inhalation.Normally used in conjunction with a mouthpiece.

1.5.35 Occupational hygiene—the application of scientific methods and principles, andthe appropriate technological and managerial measures to the overall assessment ofworking conditions.

NOTE: This includes the anticipation, recognition, evaluation, and control of the occurrence ofany substance, physical or biological agencies at or related to the workplace which wouldotherwise adversely affect the health, comfort or efficiency of the workforce, or the well-beingof their families and community.

1.5.36 Occupational hygienist—a practitioner of occupational hygiene.

1.5.37 Oxygen-deficient atmosphere—an atmosphere which does not contain enoughoxygen to fully support the body’s metabolic processes. It is generally acknowledged thatan atmospheric concentration below 18% by volume is deficient in oxygen.

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1.5.38 Oxygen generating respirator—a device which generates oxygen by means of achemical reaction for use by a wearer in a contaminated atmosphere or one lacking inoxygen.

1.5.39 Particulates—a generic term used in this Standard to refer to particulate aerosolssuch as dusts, mists, smoke, and fumes.

NOTE: As the word ‘particulate’ is defined as an adjective (not a noun) in the dictionary, thedefinition used in this Standard describes the common usage of the word in industry.

1.5.40 Particulate filter—a filter designed to remove solid or liquid aerosols or bothfrom the inhaled air.

1.5.41 Particulate filter respirator—a device consisting of a half facepiece, fullfacepiece or head covering with particulate filter or filters which remove finely dividedsolids or liquid matter from the air to be inhaled by the wearer. The filter medium may bereplaceable or be an integral part of the construction.

1.5.42 Powered air-purifying respirator—a device incorporating a half facepiece, fullfacepiece or head covering which provides the wearer with air filtered through a poweredfiltering unit, comprising a filter or filters, and an electrically operated blower unit. Thisrespirator is referred to as a PAPR.

1.5.43 Protection factor—a measure of the degree of protection afforded by therespirator, defined as the ratio of the concentration of contaminant outside the respiratorto that inside the respirator.

1.5.44 Qualitative fit test—a facial fit test giving pass/fail results and relying on thesubject’s response to a test agent.

1.5.45 Quantitative fit test—a facial fit test giving numerical results and not relying onthe subject’s response to a test agent.

1.5.46 Regulatory authority—a minister of the Crown, a government department, orcommission, or a statutory or public authority having power to issue regulations, orders,or other instructions having the force of law in respect of any subject covered by thisStandard.

NOTE: A listing of Australian regulatory, advisory and other authorities is given inAppendix B.

1.5.47 Required minimum protection factor—the protection factor required to reduceexposure to an accepted level. It is expressed as a ratio of the measured ambient airborneconcentration of a contaminant to an acceptable exposure level or standard.

1.5.48 Respirable air—air of quality intended to be suitable for human respiration (seeAppendix A).

1.5.49 Respirable dust fraction—the definition of ‘respirable’ particles is that adoptedby the British Medical Research Council (BMRC) and the recommendation of thePneumoconiosis Conference held in Johannesburg in 1959. This definition has beenadopted by Worksafe Australia and is described in AS 2985.

1.5.50 Respirator—a personal respiratory protective device which is designed to preventthe inhalation of contaminated air.

1.5.51 Self-contained breathing apparatus (SCBA)—a portable respirator whichsupplies oxygen, air or other respirable gas from a source carried by the user.

1.5.52 Single use low-boiling point filter—a category of filter intended to be usedsolely against low boiling point organic compounds during a single eight-hour shift,where the total logged period of use does not exceed the minimum specified absorptiontime of the filter. It is intended that the filter be discarded after such a period of use.

1.5.53 Shall—indicates that a statement is mandatory.

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1.5.54 Should—indicates a recommendation.

1.5.55 Smoke—particles of low vapour pressure suspended in the air. Smoke is made upfrom the solid and liquid products of combustion. Smoke particles settle slowly undergravity.

NOTE: Normally, the combustion process producing smoke also produces gases.

1.5.56 Sorbent—filter medium which captures gases by chemical or physical means.

1.5.57 Supplied-air respirator—a source of respirable air, independent of the workenvironment, which is conveyed to the person through an air line, air hose or by theperson carrying apparatus which provides the air.

1.5.58 Supplied-oxygen respirator—a device whereby oxygen is supplied from a sourceof liquid or compressed oxygen carried by the wearer.

1.5.59 Systemic effect—reactions of the body to absorbed contaminants remote from thepoint of entry.

1.5.60 Thermally generated particulates—see fume and smoke.

1.5.61 Toxicity—a substance’s potential to poison. All substances are toxic, their impactdepending on how much is required to be harmful (dose), e.g. beryllium is highly toxicand fresh water is relatively non-toxic.

1.5.62 Vapour—the gaseous form of a substance which is a solid or liquid at roomtemperature.

1.5.63 Work sets—self-contained breathing apparatus designed for general entry to orworking in an area with airborne contaminants or oxygen deficiency.

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S E C T I O N 2 E N T R Y O F S U B S T A N C E S I N T OT H E B O D Y

2.1 GENERAL In many working environments, employees are exposed to a variety ofsubstances which may be in the form of a gas, vapour, dust, mist, fume or smoke. Not allsubstances that are present in the working environment have been tested for theirtoxicological effects; however, all substances are capable of causing harm if exposure issufficiently high. For airborne substances with defined properties and known toxic effects,reference shall be made to the National Occupational Health and Safety Commissiondocument, Exposure Standards for Atmospheric Contaminants in the OccupationalEnvironment, to ensure the safety of employees.

A substance may exert a harmful effect if it comes into contact with a susceptible site inor on the body. The basic routes of entry into the body of gaseous substances areinhalation, skin absorption and ingestion. Other entry routes include skin abrasions, skinpenetration and deep wounds.

NOTE: Tobacco smoke is known to enhance the toxicological effects of some gases and manyparticulates.

2.2 INHALATION

2.2.1 General Inhalation is by far the most common route by which substances gainentry to the body. The main anatomical features of the respiratory system are shown inFigure 2.1. Air inhaled through the nose and mouth is warmed and moistened. The largeairways, or bronchii, are protected by a thick layer of mucus which is moved to the throatby millions of hair-like projections called cilia.

The small airways or bronchioles have attached to them three to six clusters of extremelysmall sacs called alveoli. There are approximately 300 million alveoli in the lungs,providing a very large surface area. The air in the alveoli is separated from bloodcapillaries by a thin membrane (0.2µm), which allows almost instantaneous transfer ofgases to and from the bloodstream.

2.2.2 Inhalation of gaseous contaminants These contaminants occur as individualmolecules similar to those in the air we breathe and so can gain easy access to thebloodstream. Gases are classified according to their effect on the body as follows:

(a) Irritants—may be gases which are readily water soluble and cause irritation of thenose and upper respiratory tract, for example ammonia (NH3) and hydrogen chloride(HCl). Alternatively, irritant gases which are relatively water insoluble, e.g. nitrogendioxide (NO2), will reach deeper into the lungs where irritation and absorption intothe bloodstream will occur.

Upper respiratory tract irritants generally have good warning properties—they areimmediately noticed and the worker will usually leave the area promptly. Lowerrespiratory tract irritants, however, are difficult to perceive initially. Often theexposed worker is unaware of their presence, as symptoms may not becomeapparent until hours later.

(b) Asphyxiants—gases which act by interfering with the supply or use of oxygen bythe body. They may be simple asphyxiants which act by diluting the availableoxygen, e.g. nitrogen (N2). Alternatively, they may be chemical asphyxiants which,even in low concentration, will be absorbed by the blood in preference to oxygen,e.g. carbon monoxide (CO) and hydrogen cyanide (HCN).

(c) Systemic poisons—gases which, once absorbed into the blood, target specific organsor body systems, e.g. carbon tetrachloride (CCl4) which causes liver damage.

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(d) Anaesthetics—gases which result in the partial or complete loss of sensation. Theireffects are similar to alcohol as such gases depress the central nervous system,initially causing mild intoxication with dizziness and loss of coordination.Continued exposure causes unconsciousness and may lead to respiratory paralysisand death. Examples include many common organic solvents, e.g. methyl ethylketone, trichloroethylene.

(e) Sensitizing agents—exposure to these gases, at even extremely low concentrations,may cause severe allergic reactions in some previously exposed individuals, e.g.toluene 2-4 di-isocyanate (TDI). Once an individual has become sensitized, theprocess is seldom reversible.

FIGURE 2.1 THE HUMAN RESPIRATORY SYSTEM

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2.2.3 Inhalation of particulates Particulates are much larger than individual moleculesand their inhalation and damage causing properties depend on such characteristics as size,shape and density, as well as physical and chemical characteristics. The potential hazarddepends on the size as well as the mass concentration because of the effects of particlesize on deposition in the respiratory tract.

2.2.4 Particle size There is a particle size range generally taken to be 0.2—10.0µmwhich is of particular importance when providing respiratory protection (see Figure 2.2).

Large particulates are not usually able to enter the lung. However, large particles ofinspirable size (up to 100µm) may be associated with systemic poisoning or sensitization,e.g. lead dust, animal protein. Very small particulates are inhaled and exhaled and maynot be retained anywhere in the lungs. Particulates in the respirable range can penetratedeep into the lungs and remain there (see Figure 2.2).

The definition of ‘respirable’ dust is that adopted by the British Medical Research Counciland the recommendation of the Pneumoconiosis Conference held in Johannesburg in 1959.This definition has been adopted by Worksafe Australia and is detailed in AS 2985. Therespirable fraction is defined by a sampling efficiency curve which depends on the settlingvelocity of the particle which passes through the points indicated in Table 2.1. This curveis often known as the ‘Johannesburg Curve’.

There are practical sampling devices which collect dust in accordance with this definition.Effectively these devices collect 100% of particles 1 micron or less, 50% of 5 micronparticles and no particles that are 7 microns or larger. All sizes refer to equivalentaerodynamic diameters.

TABLE 2.1RESPIRABLE MASS FRACTION

Particle equivalentaerodynamic diameter µm

Respirability %

01234567

1009892826850280

As with gases, particulates within the respirable size range may be classified according totheir effect on the body, as follows:

(a) Nuisance particulates—inert particulates which, when inhaled, produce no tissuechanges but may cause discomfort or minor irritation, e.g. titanium oxide (TiO2).Large quantities, however, may overwhelm the lung protection mechanisms and, inthe long term, produce injury by blocking the bronchioles.

(b) Lung-damaging dusts—particulates which reduce lung capacity by causing physicalchanges in the lung structure. Such particulates may act by giving rise to scar tissuewhich is not capable of gas exchange. Examples of lung-damaging dusts are silicaand asbestos particulates.

(c) Irritant particulates—chemically active particulates which irritate, inflame andulcerate the respiratory tract. Irritant particulates cause immediate discomfort.Examples are acid or alkaline mists.

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(d) Fever producing particulates—particulates which produce chills followed by intensefever or influenza-like symptoms. Such effects may be delayed for several hoursafter exposure. An example is the fumes evolved by welding of zinc and copperwhich give rise to ‘metal fume fever’.

(e) Systemic poisons—as with some gases, certain substances, e.g. cadmiumcompounds, in soluble particulate form may, by dissolution, enter the bloodstreamand target specific organs or systems.

(f) Sensitizing agents—particulates which even in extremely low concentrations maycause severe allergic reactions in some previously exposed persons, e.g. mould,platinum.

FIGURE 2.2 SIZE RANGE OF COMMON PARTICULATES

2.3 ABSORPTION

2.3.1 Skin absorption The intact skin normally acts as an effective barrier both againstentry into the body of, and epidermal reaction to, many substances. However, somesubstances, liquids, vapours and gases, may enter through the intact skin, e.g. heptachlor,styrene, tetraethyl lead, xylene, while others enter only through abraded skin, e.g.methomyl. These types of absorption may make a significant contribution to overallexposure.

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2.3.2 Eye absorption The effects of exposure of the eye to substances can vary fromminor irritation of the eye to total loss of vision, depending on the substance and extent ofexposure. Some substances which do not cause irritation following contact with the eyecan be absorbed into the body in sufficient amounts to cause systemic poisoning, e.g.hydrogen cyanide, sodium cyanide and some pesticides, e.g. dichlorvos, mevinphos.

2.4 INGESTION Ingestion is the process by which substances enter the body throughthe mouth (by swallowing). Depending on its physical and chemical properties, aningested substance may exert its effect on the tissue of the digestive tract or may beabsorbed and enter the bloodstream. A toxic substance may be ingested while eating,drinking or smoking in contaminated areas or by transfer to the mouth with contaminatedhands. Inhaled particles which have been deposited on the mucus in the respiratory tractwill be ingested if the mucus is swallowed.

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S E C T I O N 3 O X Y G E N - D E F I C I E N TA T M O S P H E R E S

3.1 GENERAL Particular attention should be paid to entry to or work inoxygen-deficient atmospheres (ODA). Such atmospheres may occur in confined spaces, orby chemical reaction or displacement. These conditions generally exist in areas withlimited ventilation, e.g. tanks, vats, reaction vessels, wells, tunnels, pipes, conduits, accessholes, silage pits and deep earthen trenches.

Safe procedures for working in confined spaces are not covered in this Standard. Theseare specified in AS 2865.

WARNING: THERE ARE FOUR BASIC MECHANISMS BY WHICHOXYGEN-DEFICIENT ATMOSPHERES, OR THEIR EQUIVALENT, MAYOCCUR. THESE ARE:

(1) ASCENDING TO ALTITUDE.

(2) CHEMICAL REACTION WITH SOLID PRODUCTS, E.G. THEFORMATION OF RUST OR OTHER CORROSION PRODUCTS.

(3) CHEMICAL REACTION WITH GASEOUS PRODUCTS, E.G.RESPIRATION, FIRE.

(4) DISPLACEMENT (DILUTION) BY SOME OTHER GAS ORVAPOUR.

OF THESE, ONLY THE FIRST TWO MAY RESULT IN AN OXYGENDEFICIENCY WITHOUT THE INTRODUCTION OF, OR AN INCREASE INCONCENTRATION OF, SOME OTHER GAS OR VAPOUR.

IN THE LATTER TWO CASES A SIGNIFICANT OXYGEN DEFICIENCYWILL USUALLY BE CAUSED WITH THE SIMULTANEOUS PRODUCTIONOF A TOXIC CONCENTRATION OF SUCH GAS OR VAPOUR.

3.2 ATMOSPHERIC COMPOSITION Earth’s atmosphere has an essentially fixedcomposition of the gases shown in Table 3.1.

TABLE 3.1

TYPICAL COMPOSITION OFEARTH’S ATMOSPHERE

(DRY STATE CONDITION)

Gas % composition by volume

NitrogenOxygenCarbon dioxideOther gases

78.0920.950.040.92

Other gases present in small amounts include neon, helium, and krypton. Water vapour, animportant constituent of the normal atmosphere, may be present up to 5% of the totalvolume.

Although no one definition (value) of an oxygen-deficient atmosphere has beenuniversally accepted, it is generally acknowledged that the human body can adapt tooxygen concentrations down to 18% at sea level without any noticeable adverse effects.Where a definition is required however, local legislation should be followed. Appendix Bprovides a listing of authorities who can assist in matters of local legislation.

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3.3 SYMPTOMS OF OXYGEN DEFICIENCY The symptoms of oxygen deficiencydepend on the oxygen concentration present. Table 3.2 indicates common symptomsevident at various oxygen concentrations.

At high altitudes, although the oxygen percent by volume remains constant, the amount ofoxygen available for breathing is reduced owing to the lower pressure. This may produceeffects similar to those of oxygen deficiency.

TABLE 3.2

SYMPTOMS OF OXYGEN DEFICIENCY

Oxygen volume% at sea level

Symptoms

21-18 No noticeable effect

18-14 Increased breathing volumeAccelerated heartbeatImpaired attention and thinkingImpaired coordination

14-10 Very faulty judgementVery poor muscular coordinationMuscular exertion causes rapid fatigueand may cause permanent heart damageIntermittent respiration

10-6 NauseaVomitingInability to perform vigorousmovement, or loss of all movementUnconsciousness, followed by death

Less than 6 Spasmodic breathingConvulsive movementsDeath in minutes

It is difficult for the exposed person to appreciate the effect of oxygen deficiency. Gradualdepression of the central nervous system affects powers of discrimination, logic andhearing and, when combined with attendant muscular weaknesses and lack ofcoordination, may lead to death in minutes.

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S E C T I O N 4 H A Z A R D R E C O G N I T I O N ,E V A L U A T I O N A N D C O N T R O L

4.1 RECOGNITION OF HAZARDS

4.1.1 General The recognition of hazardous situations requires detailed knowledge ofthe following:

(a) Work processes.

(b) Materials present, their physical form and properties.

(c) Intermediates or products formed.

(d) Control measures used to minimize the release of airborne substances into theworkplace atmosphere.

(e) Degree of exposure.

Knowledge of the processes, the substances used and their products will enableidentification of possible sources of airborne contaminants. Information can be gained byobserving the process in operation. For example, some processes produce dusts which mayreadily be seen. However, others may produce dusts of microscopic size which may beinvisible but which are respirable—the absence of visible dust does not mean that theatmosphere is free of particles of respirable size.

Information can also be gained by asking questions of process operators and supervisors,studying process flow sheets and identifying the composition of raw materials used.

Material safety data sheets should be obtained from manufacturers for all substances usedand similar information should be compiled for all products and by-products of processoperations.

4.1.2 Classification of inhalation hazards For the purpose of this Standard,respirators are designed to give protection against one or more of the following:

(a) Deficiency of oxygen.

(b) Contaminants in particulate form.

(c) Contaminants in gaseous form.

Respirators which are designed to give protection against all three types of atmospherichazard should be used where the type or extent of atmospheric hazard is unknown.

CAUTION: RESPIRATORS USED TO PROTECT AGAINST PARTICULATE ORGASEOUS CONTAMINANTS MAY NOT NECESSARILY PROVIDEPROTECTION AGAINST OXYGEN DEFICIENCY.

4.2 HAZARD EVALUATION

4.2.1 General Measurements of the concentration of airborne contaminants ordepletion of oxygen in the workplace atmosphere can be used to establish the existence ofa hazard by reference to current occupational exposure limits (see Clause 2.1). Evaluationof a person’s exposure may involve both personal and biological monitoring as follows:

(a) Personal monitoringThe exposure a person receives is estimated by measuring theconcentration of an airborne substance in the person’s breathing zone (air near thenose and mouth) and the duration of exposure.

(b) Environmental monitoring Measuring air contaminants in the working environmentcan give an indirect estimate of a person’s exposure and indicate the existence of apotential hazard.

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(c) Biological monitoring The measurement of levels of chemical substances or theirmetabolites, or other biochemical indicators in the appropriate biological medium ofthe body (for example in urine, blood or exhaled air). Such monitoring can, in somecircumstances, detect unexpected exposure of a person who was not suspected ofbeing in contact with the particular chemical substance. It can also be used toindicate the effectiveness of worker protection programs.

4.2.2 Exposure standards The National Occupational Health and Safety Commission(see Clause 2.1) publishes standards of exposure to airborne concentrations of individualsubstances which, according to current knowledge, should neither impair the health of, norcause undue discomfort to, most persons. These or other standards may be included instate legislation or codes of practice.

Individuals vary in their susceptibility to a given contaminant and exposure of somepersons to contaminant concentrations at or even well below the exposure standard mayresult in discomfort, aggravation of a pre-existing condition or development of anoccupational illness. The adverse effect of exposure to one contaminant may be increasedor enhanced if the person is exposed to another. For example, the effects of asbestos areexacerbated by tobacco smoke.

The best hygiene practice is to minimize any potential risk by keeping concentrations ofall airborne contaminants as low as is reasonably practicable regardless of whether theyare known to present a health hazard and irrespective of their assigned exposure standard.

4.3 HAZARD CONTROL The recognition and evaluation steps will identify theprocess that exposes a person to a hazard and evaluate the exposure which that personreceives. Three basic principles are involved in controlling employee exposure:

(a) Substitution Occupational health risks from airborne contaminants generated by acertain process might be reduced or eliminated by the substitution or modificationof a process with less hazardous materials, process equipment or by using a lesshazardous process. For example, the risks of inhaling toxic dusts might be reducedby modifying dust-producing processes to allow the application of water or othersuitable wetting agents at the source of the dust.

(b) Isolation A potential health risk will be reduced or eliminated by isolating thoseoperations likely to produce airborne contaminants from the immediate workplace.Isolation may be achieved by—

(i) installation of a physical barrier between the hazardous operation and theoperator;

(ii) locating the operator further away from the process; or

(iii) using a time delay so that the operator does not need to be in attendancewhile the process is in operation.

(c) Ventilation The control of the occupational environment by the use of airflowaccording to proved engineering principles may be used to dilute the workplaceatmosphere or to remove the contaminants at their source (local exhaust). Bothmethods may be combined with heating or cooling, or the recycling of air in theworkplace.

Wherever possible, engineering controls following the above principles should be adoptedto minimize the need for personal protective equipment. These controls are preferredbecause they do not depend on worker cooperation, proper fitting and appropriate trainingin the use of respirators. Although it should be emphasized that any procedure whichrelies on personal protective equipment as the primary control device is less than the idealsolution, there will always be situations in industry where hazardous contaminant controlprinciples cannot be fully applied. For such situations, and for secondary, back-upprotection, careful consideration should be given to the correct choice of respirators.

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S E C T I O N 5 T Y P E S O F R E S P I R A T O R

5.1 METHOD OF PROVIDING PERSONAL RESPIRATORY PROTECTIONThere are two ways of providing personal respiratory protection against atmosphericcontaminants:

(a) Purifying the air that a person breathes The inhaled air is drawn through a filterthat removes the harmful substances. The nature of the filter depends upon thecomposition and physical state of the contaminating agent. Such devices do notprovide protection in an oxygen-deficient atmosphere, or give protection against allcontaminants, e.g. there are some gases and vapours which cannot be removed byany available filter.

(b) Supplying the person with respirable air Providing a source of respirable airwhich is independent of the working environment, conveying respirable air to theperson through an air line, air hose, or by the person carrying apparatus whichprovides the air.

5.2 TYPES OF RESPIRATOR The classification of the major types of respiratordescribed in this Section is set out in Figure 5.1.

5.3 AIR-PURIFYING RESPIRATORS

5.3.1 General There are two main types of air-purifying respirator; particulaterespirators which filter out thermally and mechanically generated particulates, and gasrespirators which only filter out certain gases and vapours. In addition, filter combinationsare used where both hazard types exist.

The mode of air delivery may be either one or a combination of the following:

(a) Non-powered Air is drawn through the filter or filters by wearer inhalation. Therespirator may consist of a half facepiece with one or more replaceable filters, afiltering (disposable type) half facepiece, a full facepiece or head covering with oneor more replaceable filters, or a mouthpiece and nose clip, with integral filter.

(b) Powered The contaminated air is drawn through a filter by means of a fan anddelivered to the space enclosed by the head covering, generally under positivepressure. This respirator may be a half facepiece, full facepiece or head coveringwith one or more replaceable filters and an electrically operated blower unit. A low-flow warning device may be fitted to indicate a reduced air supply.

5.3.2 Particulate filters There are three classes of particulate filter suitable forfiltering finely divided solid or liquid particles, or both, from the inhaled air. These areclassified, in accordance with the tests in AS/NZS 1716, as follows:

(a) Class P1—intended for use against mechanically generated particulates, e.g. silica,asbestos.

(b) Class P2—intended for use against both mechanically and thermally generatedparticulates, e.g. metal fumes.

(c) Class P3—intended for use against all particulates including highly toxic materials,e.g. beryllium.

For non-powered respirators, Class P3 respirator classification can only be assigned wherea Class P3 filter is combined with a full facepiece to ensure that the effectiveness of thefacial seal is more compatible with that of the filter. Non-powered particulate respiratorswith Class P1 and Class P2 filters usually, but not exclusively, incorporate a halffacepiece.

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NOTE: This diagram excludes auxiliary protection systems (see Clause 5.4.7).

FIGURE 5.1 MAJOR TYPES OF RESPIRATORS

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Powered particulate respirators may have any facepiece or head covering regardless offilter class.

Where filters are designed for use in a PAPR, it is a requirement of AS/NZS 1716 thatthey be marked with the prefix ‘PAPR’ in conjunction with the filter description, e.g.PAPR P2.

NOTE: Manufacturers making a statement of compliance with this Australian Standard on aproduct, packaging, or promotional material related to that product are advised to ensure thatsuch compliance is capable of being verified.

5.3.3 Gas filters

5.3.3.1 General The gas filter removes certain gases from the inhaled air. The filter hasa limited useful life which varies with the volume of sorbent and the conditions underwhich it is used. Gas filters are affected by such factors as the concentration of thecontaminant in the atmosphere, the humidity, and the breathing rate of the wearer.

5.3.3.2 Types The basic types of gas filter are as follows:

Type A—for use against certain organic gases and vapours, as specified by themanufacturer.

Type B—for use against certain inorganic gases and acid gases, as specified by themanufacturer (excluding carbon monoxide).

Type E—for use against sulfur dioxide and other inorganic gases and acid gases asspecified by the manufacturer (excluding carbon monoxide).

Type G—for use against low vapour pressure chemicals, as specified by the manufacturer(vapour pressure less than 1.3 Pa [0.01 mm Hg] at 25°C), e.g. many agriculturalchemicals.

Type K—for use against ammonia and ammonia derivatives as specified by themanufacturer.

Type MB—for use against methyl bromide.

Type AX—for use against certain groups of low boiling point organic compounds asspecified by the manufacturer (boiling point less than 65°C).

Type Hg—for use against mercury vapour.

Type NO—for use against oxides of nitrogen.

Specific chemical type—for use against one or more specific chemicals not falling intoany of the above type descriptions. The filter is identified by the name of that chemical.Additional particulate filtration may be provided.

5.3.3.3 Gas filter classification The class designation relates to the total amount(capacity) of gas which can be collected by the filter, and isnot an indication of the filterefficiency.

Each gas filter may be available in one of four classes which are arranged in order ofincreasing capacity. The higher the number, the longer the filter will last for a givenconcentration of gas where other factors remain constant.

These classes are—

Class AUS—low capacity filters with a shorter life than Class 1;

Class 1—low absorption capacity filters;

Class 2—medium absorption capacity filters; and

Class 3—high absorption capacity filters.

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NOTES:

1 Filters may be required to comply with additional performance requirements if specified bya regulatory authority.

2 Some filters may provide protection against more than one gas.

3 Class AUS and Class 1 filters were previously designated as cartridges and Class 3 filters ascanisters.

4 See Table 6.4 for selection criteria.

Because of possible differences in sorbents used for each class, the physical dimensions ofClass 2 or Class 3 gas filters need not be greater than the corresponding filter of lowerclass or classes. Generally, however, a higher class number denotes a filter of greatermass and volume as well as greater absorptive capacity. The mass and bulk dictates thechoice of facepiece type and harness configuration, as required by AS/NZS 1716. Filtersare connected as follows:

(a) A filter of mass up to 300 g is connected directly to either a half or full facepiece orit may be body mounted.

(b) A filter of mass between 300 and 500 g may only be connected directly to a fullfacepiece or it may be body mounted.

(c) A filter of more than 500 g may only be body mounted.

The mass limitations are intended to minimize respirator instability and discomfort andapply to both powered and non-powered air-purifying respirators.

Non-powered half facepiece respirators either with replaceable filters or of the disposabletype generally are used with or already incorporate Class AUS, Class 1 or Class 2 gasfilters. Non-powered full facepiece respirators with replaceable gas filters are usually usedwith Class 2 or Class 3 to last longer or for higher concentrations.

Powered respirators with PAPR Class 1 or Class 2 gas filters may be used with anyfacepiece or head covering.

CAUTION: ONLY PAPR LABELLED FILTERS, SPECIFIED BY THEMANUFACTURER FOR USE IN A PARTICULAR MODEL OF POWEREDRESPIRATOR, SHALL BE USED IN THAT POWERED RESPIRATOR.

5.3.4 Combination particulate and gas filters Combination particulate and gas filtersmay have the following configurations:

(a) Filter combinations The respirator has a gas filter (as described in Clause 5.3.3)with a separate particulate filter of Class P1, P2 or P3 (as described in Clause 5.3.2)attached to it on the inlet side.

(b) Integral combined filtersThe respirator has a composite filter which, in addition toproviding protection against low concentrations of certain gases or vapours, has anintegrated particulate filter of Class P1, P2 or P3.

An external pre-filter may be added to either filter type to remove coarse particulates andso extend the life of the main filter.

NOTE: AS/NZS 1716 does not specify performance requirements for these coarse externalpre-filters.

Where gas and particulate filters are separate component parts, they must be placed insequence so that the incoming air passes through the particulate filter first.

5.3.5 Filter self-rescue respirators

5.3.5.1 General Some forms of filter respirator are designed solely for escapepurposes. There are three types as follows:

(a) Filter self-rescuer (mines).

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(b) Smoke mask.

(c) Filter self-rescuer (industrial).

5.3.5.2 Filter self-rescuer (mines) The carbon monoxide self-rescue device is arespirator for emergency use by underground miners. In the event of an explosion or fire,this equipment provides protection against particulates such as dust or smoke, and lowconcentrations of carbon monoxide and other gases as specified by the manufacturer, andenables the wearer to withdraw to a safe atmosphere.

5.3.5.3 Smoke mask The smoke mask is a respirator intended to be used only for ashort time, e.g. escape from fires. It is not intended as a substitute or replacement forSCBA apparatus or for routine use by workers. This respirator provides protection againstparticulates, such as dust or smoke, and low concentrations of carbon monoxide.Additional protection is provided against other gases commonly encountered in buildingfires. The smoke mask may be built into a simple hood made of imperviousflame-retardant material.

5.3.5.4 Filter self-rescuer (industrial) The filter self-rescuer (industrial) is designed foruse when escaping from chemical hazards that may occur in either industrial or laboratoryincidents. The respirator includes an appropriate gas filter and, depending on the nature ofthe likely hazard, may also include a particulate filter (see also Clauses 5.4.6.4 and5.4.7.2.)

5.4 SUPPLIED AIR RESPIRATORS

5.4.1 General Supplied air respirators deliver breathing air or oxygen to the wearerfrom an independent source.

5.4.2 Supplied air There are three major categories of supplied air respirator:

(a) Air-hose respirators—the air supplied in this type of respirator is not pressurized,i.e. it is at or near atmospheric pressure. The mode of air delivery may be one ofthose listed in Clauses 5.4.3(a) and 5.4.3(b)(ii).

(b) Air-line respirators—the air supplied to this type of respirator is pressurized, i.e. itis greater than atmospheric pressure. The mode of air delivery may be (b), (c) or(d), as described in Clause 5.4.3. Air-line respirators could utilize a compressor orlarge compressed gas cylinders. The air should be of the quality defined inAppendix A.

(c) Self-contained breathing apparatus—the air supplied to this type of respirator ispressurized, i.e. it is greater than atmospheric pressure. The mode of air deliverymay be (b), (c) or (d), as described in Clause 5.4.3. This apparatus uses cylinders ofcompressed air strapped to the user’s body.

NOTE: An air-line respirator may be used in conjunction with an SCBA to guard against air-line failure.

5.4.3 Mode of air delivery to the respirator The air supply for these respirators isone or a combination of the following options:

(a) Natural breathing The pressure inside the full facepiece is near atmospheric. Thenormal breathing action of the wearer draws the air into the close-fitting facepiece.A wide bore air hose is used. These respirators are normally termed hosemasks.They may also incorporate a manually-operated blower. When this type ofrespiratory protection is used, it is essential that the air-hose inlet be positionedsecurely in an uncontaminated area.

(b) Continuous flowThe volume of air supplied is more than that required by thewearer. The pressure inside the facepiece or head covering is greater than that of theimmediate environment. The pressure is controlled mainly by the degree ofrestriction to the escaping air, e.g. facial fit, outlet valve resistance, the presence of

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a neck bib and shoulder cape or integral jacket or suit. The source of air may beeither—

(i) through a compressed air line and reduced to near atmospheric pressure bythe use of a regulator or control valve; or

(ii) through an air hose connected to a low pressure electrically-operated blower.When this type of respiratory protection is used, it is essential that the airintake be positioned securely in uncontaminated air before entering anycontaminated area.

NOTE: Some self-contained breathing apparatus units of the escape type incorporatecontinuous flow.

(c) Negative pressure demandThe pressure inside the facepiece is less than that of theimmediate environment during inhalation, causing the demand valve to open,supplying air to the wearer. The demand valve shuts off completely duringexhalation. This type of system is used with a close-fitting facepiece.

(d) Positive pressure demandThe pressure within the facepiece remains greater than theimmediate environment during use. The demand valve opens to supply air to thewearer when the positive pressure inside the facepiece decreases to a presetminimum. This type of system is used with a close-fitting facepiece.

Both types of demand system may receive air either from a compressed air line or from aself-contained source. An air-hose respirator cannot be fitted with a demand valve.

5.4.4 Respirators supplied through an air hose

5.4.4.1 General Two types of respirator may be supplied through an air hose:

(a) Natural breathing type.

(b) Electrically-operated blower type.

5.4.4.2 Air-hose respirator—natural breathing type (‘hosemask’)The hosemaskcomprises a full facepiece fitted with a valve system and a breathing tube connecting thefacepiece to a relatively wide bore air hose. Air at atmospheric pressure is drawn throughthe air hose by the normal breathing action of the wearer, or supplied by a manually-operated blower.

The inlet end of the air hose is anchored in a safe location away from contamination. Thebreathing resistance of the air hose limits its length. A longer air hose may be used if theair is supplied under slight pressure by means of a manually-operated pump, blower orbellows.

5.4.4.3 Air-hose respirator—electrically-operated blower typeRespirators in this groupmay have a half facepiece, full facepiece or head covering. The air is suppliedcontinuously by an electrically-operated blower. No control valve is fitted. This type ofequipment shall not be used in immediately dangerous to life and health (IDLH)atmospheres unless an auxiliary protection system is used (see Clause 5.4.7). This allowsfor possible electrical failure.

5.4.5 Respirators supplied through an air line Respirators which are supplied from acompressed air source through a relatively small bore air line, may have a full facepiece,half facepiece or head covering.

Air-line respirators shall not be used in IDLH atmospheres unless an auxiliary protectionsystem is used (see Clause 5.4.7). This allows for possible interruption of the air supply.

5.4.6 Self-contained breathing apparatus5.4.6.1 General This class of respirator permits the wearer to move without beingrestricted by a hose or air line, in atmospheres which are contaminated to any degree orwhich are deficient in oxygen or both.

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The types of self-contained breathing apparatus (SCBA) from which the wearer obtains asupply of respirable air are as follows:

(a) Compressed air—open-circuit type.

(b) Compressed oxygen—closed-circuit type.

(c) Compressed air—open-circuit escape type.

(d) Liquid oxygen—closed-circuit type.

(e) Oxygen generating—closed-circuit type.

5.4.6.2 Compressed air—open-circuit typeCompressed air is carried in one or morecylinders and is released through a pressure demand valve and breathing tube to afacepiece or head covering from which exhaled air passes through a non-return valve tothe atmosphere. The nominal effective life of such apparatus exceeds 15 min.

5.4.6.3 Compressed oxygen—closed-circuit typeThe exhaled air passes from thefacepiece or mouthpiece through a breathing tube into a purifier containing chemicalswhich absorb the exhaled carbon dioxide, and oxygen is metered into the breathing circuitfrom a cylinder of compressed oxygen. The oxygen and purified gases mix and areinhaled by the wearer from a breathing bag and any excess gas is released through a reliefvalve.

5.4.6.4 Compressed air—open-circuit escape typeCompressed air is carried in one ormore cylinders and is released through a pressure demand or constant flow valve andbreathing tube to a full facepiece or hood from which exhaled air passes through anon-return valve to the atmosphere. The nominal effective life of such apparatus is lessthan 15 min.

5.4.6.5 Liquid oxygen—closed-circuit typeThis equipment is similar to the compressedoxygen type, except that the oxygen is supplied by evaporation of liquid oxygen containedin a tank or cylinder carried by the wearer.

5.4.6.6 Oxygen generating—closed-circuit typeThis equipment is similar to thecompressed oxygen type except that the oxygen is supplied from a container of chemicalwhich releases oxygen by reaction with water vapour and carbon dioxide in the exhaledair.

5.4.7 Auxiliary protection systems5.4.7.1 General Where routine work is to be undertaken in an atmosphere which isharmful, an auxiliary protection system should be carried for movement within the workarea or to facilitate escape. This system should provide a short-term back-up to the main,air-hose or air-line respirator. There are two types of auxiliary protection system:

(a) Self-contained breathing apparatus—escape type.

(b) Filter type.

5.4.7.2 SCBA type In this auxiliary protection system, the SCBA which may be of theescape type is attached to the wearer’s air-line system. It is designed to provide adequateprotection for a short period, thereby allowing the wearer to retreat from the contaminatedatmosphere should the air-line system fail.

5.4.7.3 Filter type This may be either a particulate and gas filter or a gas filter attachedto a supplied air system as an escape device. It is designed to provide, for short periods,adequate protection from the contaminants for which it is specifically designed.

CAUTION: THIS FILTER TYPE IS NOT SUITABLE FOR USE INOXYGEN-DEFICIENT ATMOSPHERES.

5.4.8 Low flow warning devices These may be fitted on compressed air systems towarn of reduced air supply.

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S E C T I O N 6 S E L E C T I O N O F R E S P I R A T O R S

6.1 FACTORS IN SELECTION Many points need to be considered when selecting asuitable respirator for a particular situation. It is important to ensure that only respiratoryprotective devices complying with AS/NZS 1716 be used and, where there is any doubt,expert occupational hygiene advice, such as can be obtained from State Departments ofHealth or other authorities (see Appendix B), should be sought.

To protect effectively, a respirator must be worn whenever the person is exposed to thecontaminant.

FIGURE 6.1 FLOW CHART FOR RESPIRATOR SELECTION

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The selection of respiratory protective devices will be influenced by the following factors:

(a) Contaminant.

(b) Task.

(c) Operator.

Selection guides based on identified and quantified contaminants are given in Tables 6.1to 6.6. Figure 6.1 is a work-through flow chart to determine which table to use for a givensituation. Tables 6.1 to 6.6 select respirators for specific contaminants based on the levelof protection required.

Further explanation of the recommendations is given in the rest of this Section and shouldbe read in conjunction with these tables. It is emphasized again that where there is doubtabout the correct selection, expert advice should be sought from persons experienced inrespiratory protection.

This Standard provides guidance on selection ofadequate protection. The informationshould not be viewed asminimum protection requirements. Over-specifying is warnedagainst as generally this will result in increased body burden without any improvement inprotection, e.g. formechanicallygenerated particulates such as silica dust and chrysotile,a P1 respirator will provideadequateprotection. Recommendation of a P2 respirator willprovide little or no improvement in filtration of these dusts but may have a higherbreathing resistance and therefore may force the wearer to work harder for no additionalprotection.

To ensure adequate protection is achieved at all times, it isessentialthat a full respiratoryprotection program is conducted using the guidelines provided in Section 7.

6.2 SELECTION FACTORS—CONTAMINANT-RELATED6.2.1 General The following contaminant-related factors should be considered as partof the respirator selection process:

(a) The nature, toxicity, physical form and concentration of the contaminant, whetherparticulate, gas or vapour, or a combination of these.

(b) Whether failure of the device can result in a situation which is immediatelydangerous to life or health.

(c) The need to wear other personal protective equipment e.g. eye or skin protection toprotect against irritants.

(d) The adequacy of the warning given by the contaminant.

(e) The possibility of the contaminated atmosphere being flammable.

6.2.2 Nature, toxicity, physical form and concentration of the contaminant

6.2.2.1 General Before selecting a respirator, the physical characteristics of thecontaminant or combination of contaminants needs to be known, i.e. whether it is aparticulate, a gas or a combination of them, and such conditions as the boiling point andvapour pressure.

Where the type or extent of atmospheric contamination (gaseous or particulate) remainsunknown and a safe level of oxygen cannot be assured, then devices which are designedto give protection against all three types of hazard should be used.

6.2.2.2 Protection factors and exposure standardsA major factor when selecting arespirator is to determine the reduction in exposure which a particular respirator type canbe expected to provide. This reduction, termed ‘protection factor’, is defined as the ratiobetween the concentration of a contaminant outside the respirator to the concentrationinside the respirator, i.e. breathed by the wearer. The ‘protection factor’ can also beexpressed by the following equations:

Protection factorAmbient airborne concentration

Concentration inhaled inside respirator

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Required minimum protection factor Ambient airborne concentrationAcceptable exposure level/standard

The required minimum protection factor for any given situation is that factor necessary toreduce the exposure of the wearer to below an accepted level or exposure standard or tominimize the potential exposure. A choice based upon the desired protection may be madeby referring to Tables 6.1 to 6.5.

A respirator may be selected which will ensure that the exposure level is reduced belowthe accepted level. In practice, the maximum contamination level of the ambientatmosphere for which a given respirator or class of respirator is approved may be set by aregulatory authority.

6.2.2.3 Concentration of contaminant In estimating the required minimum protectionfactor, some evaluation of the likely range of contaminant concentration in the atmosphereshould be made. (Advice should be sought from occupational hygienists on the type ofequipment, method of measurement and interpretation of test results.) The assessed levelsof contaminants, taking into account peak levels, can then be used to determine therequired protection both on a routine basis and for emergencies.

TABLE 6.1

SELECTION CONSIDERATIONSCONTAMINANT: MECHANICALLY GENERATED PARTICULATES

Required minimumprotection factor

Suitable respirator

Up to 10 • P1, P2 or P3 (see Clause 6.2.3.5) filter half facepiece—replaceable filter ordisposable facepiece

• Half facepiece air-line respirator—negative pressure demand• PAPR — P1 filter with any head covering or facepiece

Up to 50 • P2 filter in full facepiece• PAPR-P2 filter in PAPR with any head covering or full facepiece• PAPR-P3 filter in PAPR with any head covering• Half facepiece with continuous flow air line or air hose

Up to 100 • P3 filter in full facepiece• Full facepiece air-line respirator—negative pressure demand

100+ • PAPR-P3 filter in PAPR with full facepiece or head covering and blouse• Head covering air-hose or air-line respirator—continuous flow• Full facepiece air-line respirator—positive pressure demand or continuous flow

modes• Full facepiece air hose—continuous flow

CAUTION: WHERE EXPOSURE TO THE CONTAMINANT COULD BE IMMEDIATELYDANGEROUS TO LIFE OR HEALTH, SEE TABLES 6.5 AND 6.6.

NOTES:

1 The required minimum protection factor is explained in Clause 6.2.2.

2 Respirators listed as suitable for the higher protection factors are also suitable for lowerprotection factors.

3 These tables do not cover all considerations for all applications of respiratory protectivedevices and should be read in conjunction with Section 6.

4 Where the process also liberates toxic gases, see Table 6.5.

5 See Appendix C for a respirator selection example.

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Examples of processes which would result in the mechanical generation of particles:

Grinding, blasting, sanding, mixing powders, chipping, spraying.

Examples of mechanically generated particulates:

Silica dust, coal dust, asbestos fibres, lead dust, sodium hydroxide mist.

TABLE 6.2

SELECTION CONSIDERATIONS

CONTAMINANT: THERMALLY GENERATED PARTICULATES

Required minimumprotection factor

Suitable respirator

Up to 10 • P2, or P3 (see Clause 6.2.3.5) filter half facepiece—replaceable filter ordisposable facepiece

• Half facepiece air-line respirator—negative pressure demand

Up to 50 • P2 filter in full facepiece• PAPR-P2 filter in PAPR with any head covering or full facepiece• PAPR-P3 filter in PAPR with any head covering or full facepiece• Half facepiece with continuous flow air line or air hose

Up to 100 • P3 filter in full facepiece• Full facepiece air-line respirator—negative pressure demand

100+ • PAPR-P3 filter in PAPR with full facepiece or head covering and blouse• Head covering air-hose or air-line respirator—continuous flow• Full facepiece air-line respirator—positive pressure demand or continuous flow

modes

CAUTION: WHERE EXPOSURE TO THE CONTAMINANT COULD BE IMMEDIATELYDANGEROUS TO LIFE OR HEALTH, SEE TABLES 6.5 AND 6.6.

NOTES:

1 The required minimum protection factor is explained in Clause 6.2.2.

2 Respirators listed as suitable for the higher protection factors are also suitable for lowerprotection factors.

3 Where the process also releases toxic gases, see Table 6.5.

Examples of processes which result in the thermal generation of particles:

Smelting, welding, brazing, heating.

Examples of thermally generated particles:

Lead fume, zinc oxide fume, chromium fume, manganese fume, welding fume.

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TABLE 6.3

SELECTION CONSIDERATIONS

CONTAMINANT: GASES AND VAPOURS

Required minimumprotection factor

Maximum gas/vapourconcentration present inair p.p.m. (by volume)

Suitable respirator

Up to 10 1 000 • Class AUS, 1, 2 or 3 filter with halffacepiece—replaceable filter or disposablefacepiece

• Class PAPR-AUS, PAPR-1 or PAPR-2 filters inPAPR with any head covering or facepiece

• Half facepiece air-line respirator—negativepressure demand

Up to 50 1 000 • Class AUS or Class 1 filter with full facepiece

Up to 50 5 000 • Half facepiece air-line respirator—continuousflow

Up to 100 5 000 • Class 2 filter with full facepiece• Class PAPR-2 filters, filters with full facepiece

PAPR

Up to 100 10 000 • Class 3 filter with full facepiece• Full facepiece air-line respirator—negative

pressure demand• SCBA negative pressure demand

100+ • Full facepiece, head covering or air-supplied suitwith air-line respirator—positive pressure demandor continuous-flow

• SCBA positive pressure demand

CAUTION: WHERE EXPOSURE TO THE CONTAMINANT COULD BE IMMEDIATELYDANGEROUS TO LIFE OR HEALTH, SEE TABLES 6.5 AND 6.6.

NOTES:

1 The required minimum protection factor is explained in Clause 6.2.2.

2 Respirators listed as suitable for the higher protection factors are also suitable for lowerprotection factors.

3 Eye protection may be required.

4 See Appendix C for a respirator selection example.

Filter class refers to the capacity of the filter. Table 6.3 considers class (capacity) onlyand must be read in conjunction with Table 6.4 when selecting a gas filter.

Both required minimum protection factor and maximum gas/vapour concentration presentin air should not exceed those listed, e.g. where the exposure standard is 200 p.p.m. (byvolume) and the workplace concentration is 1200 p.p.m. (by volume), the requiredminimum protection factor is 6 (1200/200). However, the ambient concentration is greaterthan 1000 p.p.m. (by volume), so the appropriate respirator is chosen from the section ofthe Table commencing, ‘required minimum protection factor up to 50’. This is because aClass 1 filter would have insufficient capacity to be of practical use in such an ambientcontaminant concentration.

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TABLE 6.4

SELECTION CONSIDERATIONSFILTER TYPES FOR GASES AND VAPOURS

Filter type Descriptive name Examples of contaminants/uses

A Organic vapours Solvents (with boiling point above 65°C)

B Aus or B1 Acid gases Chlorine/sterilization of water; chemical manufacture;hydrogen chloride/chlorinated organic chemical manufacture;steel pickling

B2 Acid gas and hydrogencyanide (HCN) Plastics manufacture; gold ore refining

B3 Acid gas and hydrogencyanide (HCN)

HCN fumigation

E Sulfur dioxide (SO2) SO2/casting of metals; bleach manufacture; manufacture ofsulfuric acid; fertilizer manufacture; metal cleaning;petroleum refining

G Agriculture chemicals Low vapour pressure (below 1.3 Pa at 25°C) pesticidespraying, mixing, manufacture

K Ammonia (NH3) NH3/refrigeration; manufacture of fertilizers, explosives,plastics; low boiling point amines/chemical manufacture

Hg Mercury Metallic mercury/chemical industry; inorganic-mercurycompounds

NO Oxides of nitrogen Oxides of nitrogen

MB Methyl bromide Fumigation

AX Low boiling point organiccompounds (below 65°C)

As specified by the manufacturer, e.g. dimethyl ether, vinylchloride

Specificchemicaltype

Specific chemical name For use against specific chemicals not falling in the abovetype descriptions as specified by the manufacturer, e.g.hydrogen fluoride

NOTE: See Appendix C for a respirator selection example.

Table 6.4 lists some examples of compounds for which the differenttypesof filter shouldbe suitable.

As sorbents vary from one manufacturer to the next, it should be ensured that the filtertype selected is appropriate for all contaminants present. When in doubt, check with themanufacturer.

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TABLE 6.5

SELECTION CONSIDERATIONSRESPIRATORS FOR COMBINED PARTICULATES AND GASES

Hazard Respirator

General particulates, gases or vapourslisted in Tables 6.1, 6.2, 6.3 or 6.4

1 Integral gas and particulate filter2 Gas filter with particulate filter attachment3 Supplied-air respirator

Escape from smoke— no oxygendeficiency

Smoke-mask respirator

Escape from smoke and carbon monoxide(in an underground fire, explosion)

Filter self-rescuer (mines)

Escape from gases (industrial) Filter self-rescuer (industrial) Class 2 or 3 gas filters

TABLE 6.6

SELECTION CONSIDERATIONSRESPIRATORS FOR OXYGEN DEFICIENCY OR ATMOSPHERE

OF HIGH OR UNKNOWN CONCENTRATIONS OF CONTAMINANTS

Expected use Equipment Remarks

Escape, easyaccess

SCBA, escape type (hood) duration:5 to 8 min, according to type approval

Access to respirable atmosphereachievable at walking (6.5 km/h) pacewithin the nominal effective life ofthe apparatus of choice

Escape SCBA, escape type (full facepiece) duration:5 to 15 min, according to type approvalOxygen generating set duration:30 to 90 min, according to type approval

Duration of set limited to 5 to 15 min,(SCBA escape type) and 30 to 90 min(oxygen-generating type). No work orrescue usage

Work, routine Air-hose (hosemask) natural breathing typeAir-line or air-hose with auxiliary protection

Limited mobility and distance tosource of respirable air

Work, includingrescue use

Compressed air SCBA duration:>15 min, according to type approvalOxygen SCBAAir line with SCBA

Limited durationSpecialist training essentialLimited mobility and distance tosource of respirable air

NOTE: Where work is conducted in confined spaces, refer to AS 2865. Appendix B of this Standard providesa listing of regulatory and other authorities who can assist with local regulations.

6.2.3 Protection against particulates

6.2.3.1 General In most circumstances adequate respiratory protection againstnon-volatile particulates can be obtained by the use of a particulate respirator. The degreeof protection is governed by the type of filter and facepiece and the effectiveness of theindividual’s facial seal (see Appendices D and E).

CAUTION: DEVICES ARE AVAILABLE, MANUFACTURED FROM MATERIALSSUCH AS SYNTHETIC FIBRE, COTTON FIBRE, OR PLASTIC FOAM PADS,WHICH DO NOT COMPLY WITH THE REQUIREMENTS OF AS/NZS 1716.THESE GENERALLY HAVE AN INADEQUATE PARTICULATE FILTERINGABILITY AND WILL REMOVE ONLY COARSE PARTICLES FROM THEINHALED AIR. THEIR USE SHOULD BE ACTIVELY DISCOURAGED, AS THEYOFFER NO EFFECTIVE PROTECTION AGAINST AIRBORNE CONTAMINANTS.IN SOME STATES, LABELS INDICATING THE LIMITED USE OF THESEDEVICES ARE REQUIRED BY REGULATORY AUTHORITIES.

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6.2.3.2 Classification of filters Particulate (i.e. dust, mist, smoke and fume) filters areclassified according to their ability to filter a test cloud of particles having a sizedistribution as defined in AS/NZS 1716.

NOTES:

1 The test particles have an average size which is very much finer than that of particulatesusually found in industry.

2 Respirator users are advised that an additional gas filter or filters will be required where theprocess responsible for generating particulates also liberates toxic gases.

6.2.3.3 Class P1 filters Respirators with P1 filters are commonly used againstmechanically-generated particulates of the size most often encountered in industry, e.g.silica and chrysotile.

Three types of Class P1 respirator are generally available, i.e. powered type, replaceablefilter type and disposable type.

6.2.3.4 Class P2 filters Respirators with P2 filters are used for protection againstmechanically or thermally generated particulates or both, e.g. metal fumes.

Three types of Class P2 respirator are generally available, i.e. powered type, replaceablefilter type and disposable type.

6.2.3.5 Class P3 filters For P3 filter classification, a full facepiece is required. Theseare used for protection against highly toxic or highly irritant particulates, such asberyllium. Two types of class P3 respirator are generally available, e.g. powered type andreplaceable filter type.

6.2.3.6 Use of air-hose or air-line respirators Where the particulate concentrationcauses rapid clogging of the filter or the occupation is a routine one and does not requiregreat mobility, the use of an air-hose or an air-line respirator may be more suitable.

An air-line or air-hose respirator, used in conjunction with self-contained breathingapparatus of the escape type, is suitable for long-term use in potentially dangerous orunknown situations where an air supply failure would cause loss of protection.

6.2.4 Protection against toxic gases

6.2.4.1 General Protection against toxic gases may be obtained by the use of anair-purifying respirator or by a supplied air device. The degree of protection provided isgoverned by the type of filter used in the respirator and the effectiveness of the individualfacial seal (see Appendices D and E).

6.2.4.2 Gas filter respirator The different types of filters are specified in Clause 5.3.3,Tables 6.3 and 6.4, and AS/NZS 1716. The classes are distinguished by their gasabsorptive capacity and, in general, by their size and mass.

Class AUS and Class 1, the lowest capacity filters, are generally combined with a halffacepiece, the limiting factor of which is the adequacy of facial seal, gas capacity or lackof eye protection. Where contaminants are present in high concentrations which maycause adverse reactions or which may be allergenic, even in low exposures, half facepiecerespirators may not provide an adequate facial seal.

A high standard of respiratory protection may be obtained in toxic atmospheres notdeficient in oxygen, provided that the following requirements are met:

(a) The filter used is appropriate to the specific contaminant encountered.

(b) The concentration of contaminant in the atmosphere is below the maximum forwhich the filter is suitable.

(c) The respirator fits the wearer correctly.

(d) The protection factor afforded by the respirator is sufficiently high.

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(e) The respirator is worn while the wearer is in the contaminated area.

(f) Maintenance of the respirator is carried out when required.

6.2.4.3 Gas filter life The life of a filter is difficult to assess under normal workingconditions, being dependent on the concentration of contaminant in the atmosphere, thehumidity and the work rate of the wearer. Extreme caution should always be exercised ifthe contaminant gives no adequate warning of its presence (see Clause 6.2.8). A spentfilter should be rendered unusable and disposed of in the same manner as the contaminant,e.g. a methyl bromide filter used in a fumigation situation must be double bagged fordisposal by a competent authority (see also Appendix B). All classes of gas filter shouldbe discarded no longer than six months after opening, irrespective of the number ofperiods of use.

The manufacturer’s instructions should be observed, particularly when special filters areused.

6.2.4.4 Supplied air respirators A supplied air respirator would be required in one ormore of the situations described below:

(a) Where there is an oxygen deficiency.

(b) Where the level of toxic gases or vapours exceeds the capability of an air-filteringdevice.

(c) Where the level of contamination is unknown.

(d) Where the operator is required to remain in the contaminated environment forlonger than the estimated life of the filter.

(e) Where environments are immediately dangerous to life and health.

(f) Where there is no filter suitable for use against the contaminant.

In some circumstances, the use of a specific type or construction of supplied air respiratormay be necessary because of adverse effects of the immediate environment on parts of thebody other than the respiratory system. For example, work in a corrosive or solvent-ladenatmosphere may require the use of a full facepiece or head covering and body protection.

The materials from which the respirator is made would have to be resistant to attack fromthe specific gases or vapours present.

A full face supplied-air respirator, used in conjunction with self-contained breathingapparatus of the escape type (see Clause 5.4.7), is recommended for use in potentiallydangerous or unknown situations where an air supply failure would cause loss ofprotection (see also Clause 6.2.6).

Negative pressure air-line respirators provide protection equivalent to that provided bynon-powered air-purifying respirators, however, their use should be discouraged in favourof positive pressure, continuous flow or positive pressure demand systems.

6.2.5 Protection against combined particulates, gases and vapoursSubject to thelimitations imposed in Clauses 6.3 and 6.4, protection against the combined hazards ofparticulates, gases and vapours, e.g. spray painting, can be obtained by the use of acombined particulate and gas filter, or a respirator which is fitted with a combination offilters in series, or by the use of any of the supplied air devices.

6.2.6 Protection against oxygen-deficient atmospheresEntry to places where thenormal level of oxygen has been depleted or is unknown (see Section 3) requires eitherthe wearing of—

(a) a SCBA of sufficient operational duration; or

(b) an air-line respirator with escape SCBA attached to the person.

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Particular care should be taken in choosing an air-line or air-hose depending on whetherthey are to be used in very high temperatures, very low temperatures, or are likely tocome in contact with solvents or other deleterious materials.

6.2.7 Additional protection

6.2.7.1 General The extent of the precautions required to exclude the contaminatedatmosphere will depend on its effect on the body. Contaminants may have to be kept awayfrom the eyes and skin as well as from the respiratory tract owing to immediate irritation(see Section 2).

Depending on the type and amount of contamination in the atmosphere, a number ofrespirator types with varying facial and body coverage can protect, and if necessaryprogressively isolate the respirator user from the contaminated atmosphere. The respiratortypes range from a simple mouth piece to full-body encapsulation. Attention is also drawnto AS 3765.1 and AS 3765.2.

The degree to which the contaminant atmosphere may be excluded depends upon theeffectiveness of the facial and body seal.

6.2.7.2 Use with goggles or spectaclesMost types of filter respirator use a halffacepiece and this may interfere with the wearing of protective goggles or prescriptionspectacles. The need for separate eye protection may be avoided by the use of a fullfacepiece or a hood or helmet respirator. Prescription lens spectacles can be incorporatedwithin certain types of full facepiece.

6.2.7.3 Use with head coverings In situations where head protection from irritants isrequired in addition to respiratory protection, a hood or head covering is recommended. Itmay be worn in conjunction with a full facepiece respirator or may have integralrespiratory protection.

6.2.8 Adequacy of the warning given by the contaminant

6.2.8.1 Limitations of odour as a warning of end of filter lifeIn many cases, the firstindication of the presence of a contaminant is given by its odour, and no doubt this hasoften served as a warning against dangerous situations. For this purpose, however, thesense of smell has very serious limitations. Some of these limitations are as follows:

(a) There is considerable variation between individuals, with some persons being unableto detect contaminants by smell, e.g. hydrogen cyanide has a characteristic almondodour which is not detectable by some people.

(b) The sense of smell in an individual may be considerably diminished temporarily bya cold in the nose or other inflammatory conditions of the nasal passages.

(c) The odour of a contaminant may be masked by other smells.

(d) The sense of smell fails to detect high concentrations of many contaminants if suchconcentrations have been built up gradually, e.g. hydrogen sulfide. A personworking in a situation where a dangerous concentration of a contaminant hasdeveloped slowly may not detect any odour; yet a person entering the situation fromoutside could be aware of a very strong odour.

(e) The threshold of odour for some materials exceeds the level at which such materialsmay be considered hazardous. Thus, by the time the contaminant can be smelt, thewearer may already have been exposed to a hazardous situation, e.g. toluenedi-isocyanate (TDI).

(f) Some gases have no odour and therefore are not detectable by this means.

(g) Some gases have very objectionable odours at very low concentrations but do notrepresent a health hazard at these concentrations.

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It is therefore of fundamental importance in respiratory protection that the sense of smellshould never be relied upon to provide warning against dangerous contaminants.

6.2.8.2 Limitations of irritant action as a warning of end of filter lifeSomecontaminants, because of their local irritant action on the upper respiratory tract or eyeswill give an early indication if present in harmful amounts. The warning sensationexperienced, although perhaps centred in the nose, is not a smell, but a discomfort, afeeling of burning or irritation, e.g. sulfur dioxide.

With some contaminants, the warning symptoms are so severe that no one would willinglyremain in a dangerous atmosphere, e.g. ammonia and hydrogen chloride (HCl).

With other contaminants, the warning may be positive, but insufficient to protect a personwho is willing to endure considerable discomfort, e.g. chlorine.

6.2.9 Respirators for use in flammable or explosive atmospheresIn the selection ofrespirators for use in potentially flammable or explosive atmospheres, care should betaken to select equipment that is not likely to be an ignition source. Such ignition sourcescan include the use of certain alloys which may produce sparks on impact with rusted ironor steel, the use of plastics and fibres with unsuitable antistatic properties, electricalcomponents without a recognized method of protection or communications equipment.

Alloys suitable for use in this situation are those in which the total content of aluminiummagnesium or titanium does not exceed 15% by mass and in which the content ofmagnesium and titanium together does not exceed 6% by mass.

Non-metallic materials shall have antistatic properties complying with AS 1020.

The intrinsic safety of flameproof properties of electrical components of the equipmentshall comply with and be certified to the requirements of AS 2380.2 or AS 2380.7 asappropriate.

NOTES:

1 ‘Intrinsic safety’ is defined in AS 2380.7 in the following terms: a circuit in which anyspark or any thermal effect produced in the test conditions prescribed in this Standard(which include normal operation and specified fault condition) is incapable of causingignition of an explosive atmosphere.

2 ‘Flameproof enclosure’ is defined in AS 2380.2 as an enclosure for electrical equipment thatwill withstand, without damage, an explosion of a prescribed flammable gas or vapourwithin the enclosure and will prevent the transmission of flame such as will ignite theexternal prescribed flammable gas or vapour for which it is designed, and which operates atan external temperature that will not ignite a surrounding flammable atmosphere.

3 ‘Antistatic’ is defined in AS 1020 as indicating that a material is, by virtue of its lowresistivity, incapable of retaining a significant static charge when in contact with earth.

4 Attention is drawn to the availability of a scheme for the certification of explosion-protectedelectrical equipment. Equipment so certified conforms to one of the explosion-protectedelectrical equipment Standards listed in publication MP69.

6.3 SELECTION FACTORS—TASK-RELATED

6.3.1 General The following task-related factors should be considered as part of therespirator selection process:

(a) Whether the device is for regular use or for emergency or rescue purposes.

(b) The probable length of time during which the wearer will be in the contaminatedatmosphere.

(c) The expected level of activity and mobility required of the wearer.

(d) The access to and nature of the working environment and its location with respect toa source of air suitable for breathing.

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(e) The need for clear vision and communication.

(f) The facilities available to maintain the device.

6.3.2 Frequency and length of usage The most commonly used respirators for regularuse are half facepiece non-powered air-purifying respirators, because of their comfort andconvenience. However, where full facepiece non-powered air-purifying respirators areused, consideration should be given to limiting their use to minimize discomfort and thepossibility of heat stress.

Half facepiece non-powered air-purifying respirators are not suitable for rescue purposes.

When selecting an appropriate gas filter, the contaminant concentration, requiredminimum protection factor and period of exposure should first be addressed (seeClause 6.2.2.2, Table 6.3 and the filter manufacturer’s instructions).

With particulate filters, extended use (or even moderate use in a heavily dust-ladenatmosphere) will result in the wearer detecting an increase in breathing resistance causedby progressive blocking of the filter. Depending upon the severity of this phenomenon,users may prefer to employ supplied air equipment. Supplied air respirators are alsochosen where facilities to change filters are not immediately available.

Powered air-purifying respirators are also restricted by filter life, the necessity for filterchanges and battery charging facilities and, in addition, the battery life must be taken intoaccount (see Clause 7.8.6).

Compressed air SCBAs are most suitable for routine or emergency work, but should berestricted to short-term use owing to an average supply life of 15 to 50 min. Where longerduration is required, such as for mines rescue and firefighting, compressed oxygen orliquid oxygen SCBAs are preferred. However, the use of such equipment should belimited to specially trained and experienced personnel.

6.3.3 Degree of activity and mobility Although non-powered air-purifying respiratorsdo not restrict the mobility of the wearer, they impose a load upon the breathing processwhich may increase markedly with higher efficiency particulate filters. Where strenuousactivity is required, a supplied-air respirator or a powered air-purifying respirator may bemore comfortable. The PAPR has an advantage over air-hose or air-line equipment asthere is no restriction of mobility. If SCBA is preferred, the weight and bulk of theapparatus should be considered as these may present difficulties to the users.

6.3.4 Location of the task When contemplating supplied air respirators, considerationshould be given to the problems which may be presented by the air hose or air linelimiting the distance between the task and a source of respirable air. In addition, suchhoses or lines may be a source of danger to others working in the area and maythemselves be damaged or severed through accident. Where compressed air-linerespirators are indicated, these problems may be alleviated by supplying air from a largecylinder which may be moved to the task location. Air supplied from cylinders only lastsfor a short period when used in a continuous flow mode.

6.3.5 Vision and communication Depending upon detailed design, all full facepiecerespirators restrict the wearer’s vision to a certain extent. This should be considered if theuser needs to be near moving machinery.

Where precise communication is important, consideration should be given to selecting afacepiece with appropriate speech transmission facilities, otherwise the tendency will befor the wearer to remove the respirator to speak.

6.3.6 Maintenance Disposable respirators have a clear advantage where adequatemaintenance facilities are unavailable. All other types require varying degrees ofmaintenance. Adoption of a maintenance program is essential (see Section 8).

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6.3.7 Air-hose or air-line Particular care should be taken in choosing an air-line orair-hose. Careful consideration should also be exercised when they are intended to be usedin temperature extremes, or are likely to come in contact with solvents or otherdeleterious materials.

6.4 SELECTION FACTORS—OPERATOR-RELATED

6.4.1 General The following operator-related factors should be considered as part ofthe respirator selection process:

(a) Basic physiological considerations (see Clause 7.3).

(b) The importance of facial fit (see Clause 7.3.2).

(c) User acceptance.

6.4.2 Basic physiological considerations When selecting a suitable respirator, theeffect of the working environment upon the user should be investigated. This shouldestablish whether, when wearing a particular type of respirator, the user will be subject toadverse effects from environmental hazards other than atmospheric contamination. If thisproves to be the case, a different design which retains sufficient respiratory protection,may mitigate such hazards and increase comfort afforded to the wearer.

A common situation which exemplifies the above would be where a user of a fullfacepiece air-purifying respirator is working in an environment where he or she is subjectto a high thermal load. Continued use may well result in hyperthermia (heat stress). Theappropriate respirator in this circumstance may be an air-line respirator with coolingattachment, an air hose with a manual or electrical blower supplying cool air from anadjacent environment or a PAPR with a cooling attachment.

6.4.3 The importance of facial fit Facial fit is a prime factor in obtaining goodprotection when utilizing half or full facepiece respirators. All users must be made awareof the importance of facial fit in the selection of a respirator.

Respirators incorporating close fitting facepieces rely on facial fit to prevent inwardleakage of contaminants. Such respirators employing a full facepiece or half facepiecemust not be used by males who are not clean shaven about the cheeks, neck and jaw. Halffacepiece respirators of this type must not be used by those with moustaches where thereis any chance of hair coming between the facepiece and the skin. Long hair may alsoimpair the function of valves (see Clause 7.5.3). Nevertheless, even with an excellentfacial fit, all respirators will have some inward leakage of the ambient atmosphere as wellas the leakage through the outlet valve or valves.

Respirators which maintain a positive pressure in the facepiece at all times provide ahigher degree of protection than can be achieved with negative pressure types.

Positive pressure respirators may diminish the effect of poor facial fit but will not obviatethe effect of leakage caused by facial hair (see Clause 7.5). Where conservation of the airsupply is important, e.g. self-contained breathing apparatus, it should be recognized thatany leakage, e.g. from the facial seal, increases air consumption and decreases servicetime.

Reference should be made to Clause 7.5 and Appendix E for further information on facialfit.

6.4.4 User acceptance The appropriate respirator should be worn the entire time that aperson is at risk of exposure. In practice, the user’s adherence to this principle will beinfluenced by the wearability of the individual respirator; influencing factors includecomfort, field of vision and the need to communicate without removing the device.

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A simple calculation emphasizes the importance of wearing the respirator at all times ofexposure. In an atmosphere of 10 times the accepted exposure limit, a wearing time of atleast 95% of the exposure time is necessary to reduce the overall exposure below theaccepted safe level. This is the case irrespective of the protection factor provided by therespirator during the wearing period. The wear-time factor required for safe exposureincreases with increasing concentration of the contaminant.

When a respirator is worn routinely or for extended periods, the significance of weight,tight-fitting straps, and skin chafing will increase to the extent that the user may notconcentrate adequately on the work in hand. This translates into an increased risk ofaccident and a reduction in job satisfaction with an attendant drop in productive output.

It should be appreciated that, in some non-powered particulate air-purifying respirators,breathing resistance will increase progressively as the filter pores become blocked withcontaminants. Increasing breathing resistance in such particulate filters is thus taken toindicate the end of the filter’s effective life. Continued use, although not resulting incontaminant penetration through the filter, will impose greater discomfort on the user.

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S E C T I O N 7 T H E R E S P I R A T O R YP R O T E C T I O N P R O G R A M

7.1 MANAGEMENT RESPONSIBILITY If the control of exposure to anoccupational hazard requires the use of respirators, the purchase of such equipment formsonly a small part of the overall employer responsibility. A respiratory protection program,as outlined in this Section, shall be an integral part of a hazard control strategy.

The respiratory protection program should be established by management, and anindividual designated to head the program. The person should have a technical andprofessional background enabling him or her to make sound decisions based on anevaluation and understanding of workplace hazards. Preferably, the individual should be asafety engineer, occupational hygienist, or physician. In a small company, especiallywhere respirator usage is limited, the program may be directed by the company owner,foreperson, or other supervisory personnel. Regardless of who assumes responsibility forthe program, the responsible person should have the full support of management. Theperson should develop a standard operating procedure based upon the following:

(a) The basis for selecting a specific type of respirator.

(b) Provision for medical screening of each employee assigned to wear respirators todetermine if he or she is physically and psychologically suited.

(c) An employee training program in which the employee can become familiar with therespirators, and which includes the proper use and the limitations of the equipment.(This is discussed in detail in Appendix F.)

(d) Provision for assigning respirators to employees for their exclusive use, wherepracticable.

(e) Provision for testing for the proper fit of the respirators (see Appendices D and E).

(f) Provision for regular cleaning and disinfecting of the respirators.

(g) Provision for proper storage of the respirators.

(h) Provision for periodic inspection and maintenance of the respirators.

(i) A periodic evaluation by the administrator of the program to assure its continuedfunctioning and effectiveness.

Records of issue, fit tests, cleaning, periodic inspections and maintenance of respiratorsshould be maintained as a part of the respiratory protection program.

7.2 COMPLIANCE OF EQUIPMENT All respirators must conform with therequirements of AS/NZS 1716 where there is an appropriate category. Respirator selectionshould be based on recommendations and limitations available from Australian and NewZealand regulatory authorities.

Where a recommendation for a limitation is not available from Australian or New Zealandauthorities information governing the use of respirators may be drawn from recognizedinternational authorities.

NOTE: Recognised international authorities includes:

• National Institute for Occupational Safety and Health/Mine Safety and HealthAdministration, USA (NIOSH/MSHA).

• International Organization for Standardization (ISO).

• European Committee for Standardization (CEN).

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7.3 MEDICAL SCREENING

7.3.1 General Any type of respirator may impose some physiological andpsychological stress on the user. Persons who are routinely required to wear respiratorsshould, at least, have a medical assessment to determine if they are able to wearrespirators. As part of the assessment process, the following considerations should beevaluated:

(a) Physiological considerations Regular wearing of non-powered air-purifyingrespirators and negative pressure demand air-supplied respirators imposes an extraburden on cardiac and respiratory systems. Thus, a person with a history ofdisorders in these areas should be medically assessed by an experiencedoccupational health physician, especially where heavy work or prolonged wearing ofrespirators is anticipated.

State regulations may require regular medical examinations for some respiratorwearers, e.g. lead workers. Regular medical examinations should be considered forall employees who rely on respirators for protection from chronic industrial disease.

When assessing respirator users, consideration should also be given to the individualemployee’s ability over prolonged periods to support the weight of certainrespirators (e.g. SCBA) or to handle up to 30 m of line, if equipped with an air-linerespirator.

(b) Psychological considerations Helmet, hood and full facepiece respirators,especially when combined with full body protection, may give rise to feelings ofisolation and anxiety in some people. Such people will find it difficult to performtheir work satisfactorily under these conditions.

7.3.2 Specific factors affecting performance Some factors which may preclude theuse of respirators in situations other than escape are as follows:

(a) Chronic lung conditions such as—

(i) emphysema—the individual may be unable to breathe adequately against theadditional resistance of a respirator; and

(ii) asthma—a user suffering an asthma attack would be likely to remove therespirator because of an inability to breathe properly.

(b) Circulatory diseases such as—

(i) heart disease; and

(ii) anaemia.

(c) Epileptic seizures.

(d) Additional use of contact lenses or spectacles.

(e) Facial hair (see Clause 7.5.3).

(f) Psychological factors should also be taken into consideration when employees arerequired to wear respirators. Some individuals become claustrophobic when wearinga respirator.

(g) Facial characteristics such as scars, hollow temples, very prominent cheekbones,deep skin creases, a misshapen nose, lack of a nose bridge and lack of teeth ordentures may cause respirator facepiece sealing problems. Lack of dentures ormissing teeth may cause problems in sealing a mouthpiece in a person’s mouth. Fulldentures should be retained when wearing a respirator, but partial dentures may ormay not have to be removed, depending upon the possibility of swallowing them.

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7.4 ISSUE OF RESPIRATORS Where practical, the user should be given respiratorsfor his or her exclusive use. A record of respirator issue and usage should be establishedand maintained. This record could also show training courses attended and other relevantinformation. For respirators on extended personal issue, a system of regular cleaning,inspection and maintenance should be provided.

Respirators not issued on a personal basis, for example SCBA, should be cleaned anddisinfected after each use. No device should be issued unless it was cleaned anddisinfected after its last use. Prior to re-issue, respirators should be inspected inaccordance with the manufacturer’s instructions to ensure correct operation of therespirator.

7.5 FACIAL FIT TESTS

7.5.1 General In order for the designed performance to be achieved by a respirator, itis essential the respirator be properly fitted to the individual to whom it is assigned. Twoconsiderations are relevant to correct fitting:

(a) Assuming that there are several brands and sizes of a particular type of facepieceavailable, which one fits best?

(b) How does the user know when the respirator fits properly?

The answers to these questions can be determined by the use of a facial fit test.

There are two types of facial fit test—qualitative and quantitative. Qualitative tests areusually simple and fast. The quantitative test is not subjective but requires the purchase ofspecial equipment, and a trained operator. The significant advantage of a quantitativefacial fit test is that records can be maintained for future reference.

Appendix D describes the various types of fitting test. The program administrator shouldchoose the most appropriate of these and explain and demonstrate them to the respiratorusers.

7.5.2 Frequency of fitt ing tests Fitting tests should be performed at appropriateintervals, particularly when there is a change in the wearer’s facial characteristics, e.g.loss of teeth or excessive changes in weight, or where biological tests, e.g. lead in blood,indicate excessive exposure to a contaminant.

Facial fit tests should be adopted as a routine when any close fitting respirator is beingworn.

The following scheme of testing should be incorporated into the respirator program (seeAppendix D for test details):

(a) Before the respirator is issued, a qualitative or quantitative fit test should beperformed to assure the choice of a suitable respirator.

(b) A further facial fit test should be performed at least annually or whenever there is achange in the wearer’s facial characteristics or other features which may affect thefacial seal of the respirator.

(c) At each use, the respirator should be donned before entering the contaminated areaso the user can perform a simple positive or negative pressure fit check to test therespirator fit.

7.5.3 Facial hair in respirator fitting Facial hair lying between the sealing surface ofa respirator facepiece and the wearer’s skin will prevent a good seal. Beards, moustachesand sideburns prevent satisfactory sealing. Long hair may also interfere with the operationof exhalation valves. The sealing problem is especially critical when close fittingfacepieces are used. The reduction in pressure developed in the breathing zone of theserespirators during inhalation may lead to leakage of contaminant into the facepiece wherethere is a poor seal. Therefore, individuals who have stubble (even a few days’ growth

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will cause excessive leakage of contaminant), a moustache, sideburns, or a beard whichpasses between the skin and the sealing surface must not wear a respirator which requiresa facial seal.

Additional detail on facial hair is given in Appendix E.

7.5.4 Eye correction in respirator fitting Corrective lenses with temple bars or strapsshould not be worn if these will interfere with the facial seal. Manufacturers of respiratorscan provide kits for installing eyeglasses in their respirator facepieces. These glasses orlenses should be mounted strictly in accordance with instructions to ensure proper fitting.

Persons using half facepieces in conjunction with spectacles should be tested to ensure theeffectiveness of each device is not reduced.

7.6 CLEANING AND MAINTENANCE

7.6.1 General It is especially important that an effective storage and regularmaintenance program, appropriate to the type of respirator, be followed. Soiled ormalfunctioning respirators provide the wearers with a false sense of security. The life of awearer may be dependent on the effective operation and ready availability of a suitablerespirator. In less vital circumstances, wearer cooperation in the use of respiratoryprotective devices should be more readily forthcoming if the respirator program ensures areadily available supply of clean functional respirators.

Care of respiratory equipment should be handled by a centralized maintenance cleaningand storage station. The size and complexity of such a station will vary according to thesize of the workforce, the nature of the hazards and the type of respiratory protectiveequipment available. It should be adequately equipped and staffed by trained personnel.

All maintenance programs should follow the manufacturer’s instructions and provisionfor—

(a) cleaning and disinfection of equipment;

(b) storage;

(c) repair; and

(d) inspection for defects.

7.6.2 Cleaning and disinfection In large programs where respiratory protectiveequipment is used routinely, respirators should be cleaned daily. In small programs whererespirators are used occasionally, periodic cleaning and disinfecting is appropriate. Userswho maintain their own respirators should be trained in cleaning procedures.

After removal of any filters, the cleaning may be performed in a number of ways:

(a) The respirator should be washed with detergent in warm water using a soft brush,thoroughly rinsed in clean water, and then air-dried in a clean place. Care should betaken to prevent damage from rough handling. This method is an accepted procedurefor a small respirator program or where each worker cleans his or her ownrespirator.

(b) A standard domestic clothes washer may be used if a rack is installed to hold thefacepieces in a fixed position. (If the facepieces are placed loose in a washer, theagitator may damage them.) This method is especially useful in large programswhere respirator usage is extensive.

Caution should be observed with respect to the addition of soaps and detergents to thecleaning water. Some of these may damage the equipment or cause irritation to thewearer.

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Disinfection may be achieved by using a broad-spectrum disinfectant. The choice ofpreparation should be made after enquiring of the respirator manufacturer and medicalauthorities. Such enquiries should also assist where protection against the transmission ofa specific pathogen is required. With all disinfectants, particular attention should be paidto the manufacturer’s instructions regarding their use, e.g. dilution, temperature, exposuretime.

The cleaned and disinfected respirators should be rinsed thoroughly in clean water toremove all traces of cleaning agent and disinfectant. This is very important to preventdermatitis. After rinsing, an anti-fog preparation may be applied to lenses and visors.

The respirators should be allowed to air dry away from direct sunlight, on a clean surface,or dried in a low-temperature oven. They may also be hung from a horizontal wire, likedrying clothes, but care should be taken not to damage the facepieces.

7.6.3 Storage of equipment Respirators should be located as close as practicable tothe workplace. Respirators provided for emergency and rescue work should be at locationswhere they are readily available but adequately stored, secured and supervised so thatunauthorized use or tampering is prevented.

All emergency locations should be clearly marked in green and white in accordance withthe requirements of AS 1319. Painting green and white diagonal stripes over an area ofabout 1 m2 has been found to be a satisfactory method of marking such locations.

Cylinders of compressed oxygen or air shall be fully charged to the recommendedworking pressure.

All self-contained breathing apparatus and emergency escape equipment should bemaintained and stored in a ready for immediate operational use condition.

Carbon dioxide absorbent in self-contained compressed oxygen respirators shall berenewed at intervals defined by the manufacturer and after each operational use.

The following shall be observed for storage and protection:

(a) Respiratory protective devices shall be kept clean and dry, and away from oil andexposure to direct sunlight and corrosive atmospheres, to avoid deterioration.

(b) Where their use is infrequent, it is desirable to enclose facepieces to protect themfrom dust and corrosive atmospheres. Facepieces shall be stored so that they are notsubject to distortion.

(c) To prevent tampering, filters should be stored in sealed containers bearing the dateof the last inspection. The limited life of stored gas filters shall not be overlooked.

(d) Equipment for emergency use and not permanently issued to individuals should bestored close to the most likely points of use.

(e) Cylinders shall be recharged before the contents have dropped to below 80% of fullworking pressure.

7.6.4 Maintenance Continued use of the respirator may necessitate periodic repair orreplacement of its components. Such repairs and parts replacement should be carried outby trained individuals.

Replacement of parts and repair of air-purifying respirators should, in most cases, presentlittle problem. Equipment manufacturers supply literature which details the components oftheir respirators and also includes servicing information. The manufacturer will alsoprovide replacement parts. Replacement parts for respiratory protective equipment,including filters, should be those approved by the manufacturer of the equipment.

CAUTION: SUBSTITUTION OF PARTS OR FILTERS FROM A DIFFERENTBRAND OR TYPE OF RESPIRATOR WILL INVALIDATE THE APPROVAL OFTHE RESPIRATOR AND MAY CONTRAVENE STATE LEGISLATION.

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Defective air-supplied respirators may be repaired and used again if broken parts arereplaced by personnel authorized by the manufacturer. Maintenance of SCBA equipmentis more difficult, primarily because of the valve and regulator assembly.

NOTE: Disposable respirators are not intended to be repaired. Any attempted repair ofdisposable respirators is to be actively discouraged.

7.7 INSPECTION FOR DEFECTS

7.7.1 General An important part of a respirator maintenance program is inspection ofthe devices. If performed carefully, inspections will identify damaged or malfunctioningrespirators.

7.7.2 Inspection schedules All respiratory protective equipment should be inspected—

(a) before and after each use; and

(b) during cleaning.

In addition, SCBA and equipment designated for emergency use should be inspected inaccordance with the manufacturer’s specifications.

7.7.3 Record keeping A record shall be kept of inspection dates and findings for allrespirators maintained for emergency use.

Maintenance records should be kept for all respirators together with the periods of use ofeach filter and battery, where applicable. Extra caution should be observed when it isproposed to re-use a filter which has had prior use. (Some filters can only be used once,e.g. filter self-rescuer (mines).)

Records need not be kept for disposable respirators or for filters used in half facepiecerespirators where these are changed regularly. (See Clause 7.8.4, 7.10 and 7.11.)

Where equipment is issued to an individual, each respirator should bear an identifyingmark which may be the user’s name, initials, clock number, or other similar identification.

The date of issue and subsequent resistance checks, and the identifying mark of thefacepiece with which it is used, shall be permanently marked on the filter, if it is to bere-used.

7.8 INSPECTION AND MAINTENANCE CONSIDERATIONS

7.8.1 General This Clause itemizes some of the primary defects to look for wheninspecting a respirator. Where appropriate, suggested actions are given in parentheses. Inmany cases, the inspector may need to contact the manufacturer of the equipment or theequipment vendor.

7.8.2 Disposable respirators Inspect—

(a) for physical damage such as holes in the filter [obtain new disposable respirator];

(b) straps for elasticity and deterioration [replace respirator or straps—contactmanufacturer]; and

(c) the metal nose clip for deterioration [obtain new disposable respirator].

7.8.3 Re-usable air-purifying respirators (half facepiece, full facepiece)

7.8.3.1 Rubber facepiece Inspect for—

(a) dirt [clean all dirt from the facepiece];

(b) cracks, tears, or holes [obtain a new facepiece];

(c) distortion [allow the facepiece to ‘sit’ free from any constraints and see if distortiondisappears; if not, obtain a new facepiece]; and

(d) cracked, scratched, or loose-fitting lenses [contact respirator manufacturer to see if areplacement is possible; otherwise, obtain new facepiece].

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7.8.3.2 Headstraps Inspect for—

(a) breaks or tears [replace head harness];

(b) loss of elasticity [replace head harness];

(c) broken or malfunctioning buckles or attachments [obtain new buckles]; and

(d) excessively worn serrations on the head harness which may allow the facepiece toslip [replace head harness].

7.8.3.3 Inhalation valve, exhalation valveInspect for—

(a) detergent residue, dust particles, or dirt on valve or valve seat [clean residue withsoap and water];

(b) cracks, tears, or distortion in the valve material or valve seat [contact manufacturerfor instructions]; and

(c) missing or defective valve cover [obtain new valve cover from manufacturer].

NOTE: Permissible leakage of outlet valves may be exceeded after a relatively short life. Thisvalve defect is not always recognizable by observation and frequent checks should be made forvalve leakage. In the case of full facepiece respirators, valve assemblies should be tested afterremoval and replacement of valves. Valve leakage can be measured as shown in Appendix G.

7.8.3.4 Filter element(s) Inspect for—

(a) recommended filter for the hazard;

(b) approval conditions, where applicable;

(c) increased filter resistance [replace filter];

(d) missing or worn gaskets [contact manufacturer for a replacement];

(e) worn threads—both filter threads and facepiece threads [replace filter or facepiece,whichever is applicable];

(f) cracks or dents in filter housing [replace filter];

(g) deterioration of gas filter support harness [replace the harness]; and

(h) service life indicator, or end of service date [replace filter].

7.8.3.5 Corrugated breathing tube Inspect for—

(a) cracks or holes [replace tube];

(b) missing or loose hose clamps [obtain new clamps]; and

(c) broken or missing end connectors [obtain new connectors].

7.8.3.6 Powered air-purifying respirators Inspect as follows:

(a) Check the respirator assembly for leaks, tighten filter clamps and replace damagedparts.

(b) Check the flow rate prior to use. If the flow rate is low, check the battery andrecharge if necessary (see Clause 7.8.6) or replace the filter, or both.

(c) Check flow rate at the end of use. If rate is below minimum specified bymanufacturer, replace filter. If still below minimum, check for battery or majorfaults.

7.8.4 Supplied-air respirators

7.8.4.1 Facepiece, headstraps, valves, and breathing tubeCheck as for air-purifyingrespirators.

7.8.4.2 Hood, helmet, blouse, or full suitInspect for—

(a) rips and torn seams [if unable to repair the tear adequately, replace];

(b) headgear suspension [adjust or replace as required];

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(c) cracks or breaks in visor [replace visor];

(d) integrity and proper fit of protective screen [adjust or replace facepiece or screen asrequired]; and

(e) leaking gloves or boots [replace].

7.8.4.3 Air supply system Inspect for—

(a) breathing air quality (see Appendix A), ensure that breathing air filtration systemswhere required are in accordance with Appendix H;

(b) breaks or kinks in air-hoses and end fitting attachments [replace hose or fitting];

(c) tightness of connections;

(d) proper setting of regulators, valves and alarm systems [consult manufacturer’srecommendations]; and

(e) correct operation of air-purifying elements and carbon monoxide or other warningdevices.

7.8.4.4 Self-contained breathing apparatus (SCBA)Consult manufacturer’s literaturefor applicable inspection criteria.

7.8.5 Filter self-rescuer (mines) Because the catalyst in this equipment deteriorates onexposure to atmosphere, the complete equipment shall be stored in its sealed carryingcase. Routine examination should consist of a visual inspection for dents in the case andto ensure that the seal is unbroken, and weighing of the complete respirator. If weighingshows an increase greater than 1% in mass, the equipment should be discarded or returnedto the manufacturer for filter element replacement and resealing.

When a batch of these respirators is nearing the end of guaranteed storage life, randomsamples should be selected for complete testing by a competent authority in accordancewith AS/NZS 1716.

The guidance of the competent authority should be followed in relation to any batch ofequipment which has been so tested.

7.8.6 Care of rechargeable batteries Powered air-purifying respirators normallyemploy nickel cadmium (NiCd) rechargeable batteries to power the air blower. This typeof battery will normally withstand approximately 1000 charge/discharge cycles undertypical use conditions and may be stored for long periods in the charged or dischargedstate without ill effect.

The following points should be observed to properly care for the batteries:

(a) NiCd batteries undergo a process of continual ‘self discharge’ which, for a fullycharged battery stored at ambient temperatures in excess of 30°C, means thatdischarge will be complete after several weeks.

(b) New or stored batteries should be preconditioned prior to use. This involvessubjecting the battery to two full charge/discharge cycles and a final full charge justbefore use. Each charge/discharge cycle consists of a 14 h charge followed bydischarge under normal load conditions lasting at least 10 h.

(c) Constant current charging should be adopted for batteries in service to assureconsistent charge life. Fast charging should be avoided if possible since the resultantelevated temperature can reduce the battery’s effective life.

(d) Where normal use involves only partial discharge, batteries should be subjectedperiodically to a full discharge/recharge cycle. This is to overcome an apparentreduction in the charge life of the battery or ‘memory’ effect which may otherwisedevelop.

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(e) When considering the pattern of use for the PAPR, it should be borne in mind thatNiCd batteries display a characteristic sudden voltage drop at the end of the chargeperiod. This will be of concern to the user who expects the batteries to ‘fade out’progressively.

(f) Batteries should be stored in a dry environment, at normal room temperatures andfree from corrosive liquids and gases.

To maintain an optimum charge life, the manufacturer’s recommendations on use shouldbe followed. Where it is necessary to reconfirm the nominated charge life, the battery orbatteries should be given a full charge and then fitted to a PAPR, the facepiece of whichis attached to a flowrate/pressure measuring device. The PAPR is operated as it would bein the field and the flowrate/pressure monitored as the battery discharges.

7.8.7 Final inspection Assembled respirators should be carefully checked to ensurethat all component parts are in place and all moisture has been removed from surfaces andcrevices. Where practicable, all parts through which air is supplied to the wearer shouldbe checked for correct assembly.

7.9 SAFE WORKING PRACTICES

7.9.1 General Before entry into any area where respiratory protection may be required,it is essential that the likely contaminants, their toxicity and concentration, and thepossibility of an oxygen deficiency be known. If there is doubt on any of these points, theworst condition should be assumed and appropriate precautions should be taken,particularly in the choice of suitable equipment.

7.9.2 Provision of assistance It is essential that whenever any respirator is used in anatmosphere dangerous on short exposure, an assistant suitably trained and equipped forentering the dangerous atmosphere be standing by in continuous supervision of thewearer, either directly or with the aid of a signalling device and be able to initiate rescueif the need arises. Such supervision should include constant monitoring of the air supply,where applicable, and constant awareness of the length of time of exposure.

Prior to attempting a rescue, the assistant should raise an alarm or contact a third party.

7.9.3 Use of speech transmission devicesSpeech can cause facepiece or componentleakage and should be limited, particularly when a half facepiece is being worn. Somefacepieces are provided with speech amplification or transmission devices. If a facepieceis fitted with a mechanical speech transmission device, the diaphragm should be handledcarefully to prevent puncture. Electrically operated speech transmission devices areavailable. (See also Clause 6.2.9.)

7.9.4 Entry to confined spaces Working in confined spaces presents special problemswhich may include the difficulties of entry and escape, the possibility of oxygendeficiency and the greater likelihood of high concentrations of contaminants. Safe entry isoften covered by mandatory requirements and the appropriate statutes should be observed.In general, no entry should be attempted unless the proper equipment is available andadequate assistance (see Clause 7.9.2) is provided. Only air-supplied or oxygen-suppliedrespirators are suitable for unknown or IDLH atmospheres and any person entering theconfined space should be equipped with a safety harness and lifeline.

A full discussion of the factors affecting entry to confined spaces can be found inAS 2865.

NOTE: Attention is drawn to the additional requirements of regulatory authorities governingentry to confined spaces.

7.9.5 Low and high temperature7.9.5.1 Low temperatures Use of respirators in low temperatures can create severalproblems. The lenses of the full facepiece equipment may fog owing to condensation ofthe water vapour in the exhaled breath. Coating the inner surface of the lens with ananti-fogging compound will reduce fogging.

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7.9.5.2 High temperatures Respirator usage in hot environments can put additionalstress on the user. The stress may be minimized by using a light-weight respirator withlow breathing resistance. In this respect, an air-line respirator equipped with a coolingsystem may be used.

7.9.6 Use of hoses Care should be taken when using a hose in an area where solventsor other chemicals are used since the solvent may permeate certain types of hose material,or destroy hoses. Heat may also cause the release of objectionable odours into the hose.

7.10 REPLACEMENT OF FILTERS

7.10.1 General There is no overall rule about when filters should be changed. Eachsituation needs to be treated individually.

Advice should be sought from an occupational hygienist on an acceptable change-overtime based on likely exposure patterns, so an adequate safety margin is allowed.

WARNING: IN SOME FILTER ASSEMBLIES IT MAY BE POSSIBLE TOINSERT THE FILTER IN EITHER DIRECTION DESPITE DIRECTIONALARROWS OR INSTRUCTIONS. IF A PREVIOUSLY USED FILTER ISREINSERTED THE OTHER WAY ROUND THEN THE USER IS LIKELY TOINHALE CONTAMINANTS DEPOSITED DURING THE EARLIER USE.

7.10.2 Particulate respirators The breathing resistance of the filter will progressivelyincrease in use as it becomes choked with trapped particles and eventually becomes sohigh that the filter must be replaced. The time taken for this condition to develop willvary according to the characteristics of the filter, and the type, size and concentration ofthe particles.

As a general guide, the breathing resistance can be considered too high when there is aperceived increase in resistance to breathing. Resistance of particulate filters may beconsiderably increased if used in damp conditions. A damaged or ineffective inlet valvemay lead to condensation on the filter, thereby increasing resistance.

In the case of powered air-purifying respirators, clogging of the filters is normallysignalled by a fall in the air-flow rate.

The use of a pre-filter is advantageous where coarse particulates would otherwise rapidlychoke the filter.

Resistance of filters can be measured by the method described in Appendix I.

The use of backflushing or other methods to prolong the life of a particulate filter is to beactively discouraged since it will reduce the efficiency of the filter.

7.10.3 Gas respirators Filters should be replaced on a regular basis or when an odouror taste is perceived in the inhaled air or when the wearer coughs or experiencesdiscomfort. The breathing resistance does not normally rise during use.

The life of gas filters used in powered air-purifying respirators is dependent upon theconcentration of the contaminant, the class of filter and the flow rate of the blower unit. Itis generally independent of the wearer’s breathing rate.

Where rapid failure occurs with a new filter, the adequacy of this equipment for theapplication should be re-assessed and it may be necessary to use a more effective methodof respiratory protection.

7.10.4 Combined respirators The observations in Clauses 7.10.2 and 7.10.3 applyalso to combined respirators. In addition, where an operation which generates both gasesand particulates, such as spray painting, is being carried out, the use of a replaceablepre-filter is recommended to extend the life of the particulate filter by preventing it frombecoming clogged with coarse particulates. This pre-filter should be changed frequently.

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7.11 ENSURING THE CONTINUED EFFECTIVENESS OF THE RESPIRATORPROGRAM

7.11.1 General Two important ways of ensuring the continued effectiveness of therespirator program are the periodic monitoring of the work areas requiring usage ofrespirators, and evaluation of the overall respirator program.

7.11.2 Monitoring of atmospheric contaminant concentration Many things such aschanges in operation or process, implementation of engineering controls, temperature, andair movement can affect the concentration of the atmospheric contaminant whichoriginally required the use of respirators. To determine the continued necessity ofrespiratory protection or need for additional protection, measurements of the atmosphericcontaminant concentration should be made whenever any of the above changes are madeor detected. A record of these measurements should be kept.

7.11.3 Program evaluation In general, the respirator program should be evaluated atleast annually, with adjustments, as appropriate, made to reflect the evaluation results.Program function can be separated into administration and operation. Appendix J containsa list of check points to facilitate effective evaluation of a respirator program.

7.12 TRAINING IN RESPIRATORY PROTECTION USAGE Occupational healthand safety legislation varies from State to State, but in all cases requires employees to beadequately trained and supervised to carry out their work safely.

Where a respirator program is adopted, training should be given. This should occur at thecommencement of employment, and at routine intervals thereafter. The frequency ofretraining will depend on the complexity of the program and the degree of the hazard, butin any case, should be at least annually.

Employees who need to wear respirators should to be trained in the safe use andlimitations of the respirator. Supervisors need to be trained in their responsibilities fortraining and inspection.

Special care should be taken when training non-English-speaking employees or thosespeaking English as a second language to ensure that instructions are fully understood.

A suggested format for a respirator training program is given in Appendix F.

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S E C T I O N 8 S P E C I F I C M A I N T E N A N C ER E Q U I R E M E N T S

8.1 SERVICING FACEPIECES Where fitted, facepieces and breathing tubes ofnon-disposable respirators should be detached from the remainder of the apparatus. Whereinspection indicates distortion, cracks, hardening, tackiness or other abnormalities, themask or breathing tube should be replaced. The personal preference of the wearer withrespect to the adjustment of straps, buckles and other component parts contributing topersonal comfort, should be given due consideration when inspecting the facepiece.

8.2 SERVICING EXHALATION VALVES Wherever practicable, exhalation valvesshould be removed from valve seats and cleaned each time the respirator is serviced.Valves and valve seats may be cleaned in cold or lukewarm water (hot water should beavoided). Valve seats may need to be scrubbed with a suitable brush.

NOTE: Reference should be made to the manufacturer’s instructions for cleaning anddisinfecting facepieces. Generally, cleaning and disinfecting solutions should not be hotter than55°C as higher temperatures can permanently distort facepieces and cause prematuredeterioration of individual components or the whole assembly.

8.3 SERVICING OTHER COMPONENT PARTS In the case of component partsother than those referred to in the foregoing clauses, the following requirements forservicing should be applied:

(a) Although it is essential that water does not enter adjustment valves, reducing valves,demand valves, pressure gauges and other controlling devices, component partsshould be appropriately washed or cleaned as prescribed in the foregoing clauses.

(b) All parts should be inspected and faulty component parts replaced with thoseapproved by the manufacturer. In the case of simple items such as outlet valverubbers and head harnesses, this should be done by maintenance personnel, but forcomplex parts such as demand valves and reducing valves, servicing should only beundertaken by trained and authorized personnel.

(c) Compressed air or oxygen cylinders should be filled, inspected, tested andmaintained in accordance with the requirements of AS 2030. Partly used cylindersshould be recharged as soon as possible after use.

(d) Carbon dioxide absorbent should be recharged at intervals specified by themanufacturer.

(e) In all cases the manufacturer’s instructions should be observed when servicingself-contained breathing apparatus.

CAUTION: OIL OR GREASE SHOULD NOT BE USED ON ANY OXYGEN ORHIGH-PRESSURE AIR EQUIPMENT BECAUSE OF THE RISK OF EXPLOSION.SPECIAL LUBRICANTS ARE AVAILABLE FOR HIGH-PRESSURE (ABOVE100 MPa) AIR AND OXYGEN EQUIPMENT.

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APPENDIX A

REQUIREMENTS FOR AIR QUALITY (COMPRESSORS OR CYLINDERS)FOR SUPPLIED AIR RESPIRATORS

(Normative)

A1 AIR SUPPLY

A1.1 Capacity The necessary capacity of any air service for respiratory protectionshall be calculated on a minimum requirement of 170 litres per minute for each personmeasured at the respirator.

NOTE: Where air cooling or encapsulated suits are used additional air will be required andadvice should be sought from a competent source.

Air used to supply respirators shall—

(a) have no objectionable or nauseous odour; and

(b) contain not less than 19.5% and not more than 22% by volume of oxygen.

Additionally, at 15°C and 100 kPa absolute the air shall—

(i) contain not more than 11 mg/m3 (10 p.p.m. by volume) of carbon monoxide;

(ii) contain not more than 1400 mg/m3 (800 p.p.m. by volume) of carbon dioxide;

(iii) contain not more than 1 mg/m3 of oil; and

(iv) for cylinders, contain not more than 100 mg/m3 of water when sampled from acylinder initially filled to a pressure of at least 12 MPa.

A1.2 Air temperature Air supplied from a compressor to a facepiece, hood or helmetshould be at a comfortable breathing temperature within the range 15 to 25°C.

A1.3 Avoidance of stale air or moisture Arrangements should be made to avoid thepocketing of stale air in pipelines. The use of ring circuits and controlled draining helpsto guard against this hazard.

Couplings should be of the ‘safety type’ i.e. requiring at least two deliberate actions toseparate the connector or coupling and should be of a different design to those used forother compressed gas and air services.

NOTE: The contents of all piping, conduits ducts and other services should be identified andsuitably marked to prevent incorrect connection of air-lines. Attention is drawn to AS 1345regarding the identification of services.

Provision should also be made, at appropriate places, to drain away water from anypipeline. Water traps should be drained prior to using the apparatus.

A1.4 Compressors Systems shall incorporate a receiver of sufficient capacity to reducepulsations from compressor action and reduce compressor overheating. Compressors shallbe well maintained and shall not be allowed to run hot, as harmful substances may beproduced by the decomposition of the lubricating oils. Filters should be purged orreplaced at regular intervals in accordance with the manufacturer’s instructions.Consideration should also be given to the use of oil-free compressors.

The air intake to the compressors should be sited in an uncontaminated atmosphere.Particular care should be taken to ensure that this requirement is met if a portable aircompressor is being used to supply breathing air.

The use of filters on any air intake should be of secondary importance when comparedwith the foregoing requirements.

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A1.5 General works air supply systems Where the air supply is used in themanufacturing process as well as in the supply of respirable air, particular care should betaken to avoid the risk of contamination.

Where the air supply is used in the manufacturing process and there is a risk ofcontamination, the air supply should not be used for personal protection unless it has beenfiltered to provide the air quality defined in Paragraph A1.1.

In every instance it should be ensured that any back pressures from operating plants usingthe air supply will not cause contamination of the air used for personal protection.

Provision should be made to ensure that the air lines supplying the breathing apparatusreceive an adequate supply of respirable air under all plant operating conditions.

Plant air supplies are not suitable for air-line respirators unless special precautions havebeen taken for the elimination of scale, rust, water, oil mist, irritating ingredients andodours. It is preferable that a separate installation be provided for respiratory air purposes,and that it be designed to eliminate the abovementioned contaminants.

A1.6 Air quality Regular testing of the air at the respirator shall be undertaken toverify the quality of the air and records kept.

A2 COMPRESSED OXYGEN SUPPLY Compressed oxygen of the dry breathingtype should be odourless and contain not less than 99.5% by volume of oxygen.

At 15°C and 100 kPa absolute, it should contain—

(a) less than 11 mg/m3 (10 p.p.m. by volume) carbon monoxide; and

(b) less than 1400 mg/m3 (800 p.p.m. by volume) carbon dioxide.

When sampled from a cylinder initially filled to at least 12 MPa, it should contain—

(i) less than 20 mg/m3 water; and

(ii) less than 1 mg/m3 oil.

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APPENDIX B

ADVISORY AUTHORITIES

(Informative)

Advice and assistance on various aspects of occupational hazards and relevant exposurelimits as well as regulatory requirements may be obtained from the following authorities:

AUSTRALIAN CAPITAL TERRITORY

Australian Capital Territory Telephone: (06) 247 2899Radiation Safety Section Fax: (06) 257 3503GPO Box 825CANBERRA CITY ACT 2601

COMMONWEALTH

Comcare Australia Telephone: (06) 275 0000GPO Box 9905 Fax: (06) 247 2231CANBERRA ACT 2601

NEW SOUTH WALES

WorkCover Authority of NSW Telephone: (02) 370 5301400 Kent StreetSYDNEY NSW 2000

Radiation Control Section Telephone: (02) 795 5000Environmental Protection Authority Fax: (02) 649 4470PO Box 136REGENTS PARK NSW 2143

NORTHERN TERRITORY

Occupational and Environmental Health Telephone: (089) 89 2983Health Branch Fax: (089) 89 2700Department of Health and Community ServicesGPO Box 1701,DARWIN NT 0801

Northern Territory Work Health Authority Telephone: (089) 89 551166 Esplanade StreetDARWIN NT 0801

QUEENSLAND

Division of Health and Medical Physics Telephone: (07) 252 5446Department of Health Fax: (07) 252 9021450 Gregory TerraceFORTITUDE VALLEY QLD 4006

Queensland Health Telephone: (07) 274 9111Scientific ServicesGovernment Chemical Laboratory39 Kessels RoadCOOPERS PLAINS QLD 4108

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Department of Employment, Vocational Telephone: (07) 857 9490Education, Training and Industrial Fax: (07) 857 9426RelationsDivision of Workplace Health and SafetyForbes House30 Makerston StreetBRISBANE QLD 4000

SOUTH AUSTRALIA

South Australian Occupational Health Telephone: (08) 226 3120and Safety Commission Fax: (08) 212 1864100 Waymouth StreetADELAIDE SA 5000

Department of Labour Telephone (08) 226 6510Occupational Health Division Fax: (08) 232 033461 Hindmarsh SquareADELAIDE SA 5000

Radiation Protection Branch Telephone: (08) 226 6521South Australian Health Commission Fax: (08) 226 6255PO Box 6Rundle MallADELAIDE SA 5000

TASMANIA

Occupational Health and Safety Telephone: (002) 33 766881-89 Brisbane StreetHOBART TAS 7001

Senior Health Physicist Telephone: (002) 30 3770Department of Health Fax: (002) 310735GPO Box 191BHOBART TAS 7001

VICTORIA

Occupational Health and Safety Authority Telephone: (03) 655 644480 Collins StreetMELBOURNE VIC 3000

Radiation Safety Section Telephone: (03) 616 7084Health Department Victoria Fax: (03) 616 7147GPO Box 4003MELBOURNE VIC 3000

WESTERN AUSTRALIA

Department of Occupational Health, Telephone: (09) 327 8777Safety and Welfare Fax: (09) 321 89731260 Hay StreetWEST PERTH WA 6005

Radiation Health Section Telephone: (09) 346 2261Health Department of Western Australia Fax: (09) 381 1423GPO Box X2307PERTH WA 6001

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APPENDIX C

RESPIRATOR SELECTION EXAMPLES

(Informative)

C1 EXAMPLE 1

TASK: Tunnelling in rock containing quartz for 8—10 hours per day.

PARTICULATE MEASUREMENTS:Tunnelling machine operator 1.5 mg/m3 respirable

quartz (TWA)*

Other workers in vicinity ofoperatorExposure standard— respirablequartz

0.3−0.5 mg/m3 (TWA)*0.1 mg/m3 (TWA)*

RESPIRATOR SELECTION: Tunnelling machineoperator

Other workers

Required protection factor(see Clause 6.2.2.2)

15 5

Other protective equipmentrequired

Safety helmet, hearingprotection, miner’s lamp,faceshield and eyeprotection

Safety helmet, hearingprotection, miner’s lampand eye protection

General choice (Table 6.1) — PAPR P2— P2 filter in a full

facepiece— Half facepiece air-

line respirator

— P1 half facepiece

Final selection — Helmet type PAPRfittedwith lamp bracket andearmuffs

— P1 disposable

Reasons for choice Air-line unsuitable due tolack of mobility. Fullfacepiece unsuitable forextended usage

Personal choice— light-weight, no maintenancerequired

C2 EXAMPLE 2

TASK: Manufacturing operation requiring addition of volatile solvents to a batching tank.Engineering controls not yet operational. Operation performed once per day for half an hour.

GAS/VAPOUR MEASUREMENT:

During addition of solvent 1500 mg/m3 methyl ethyl ketone (MEK) (peakconcentration)3 respirable

Exposure standard, MEK 445/m3

* (TWA) time-weighted average.

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Required minimum protection factor 4

General choice (Table 6.3) — Type A AUS for Type A1 gas filter with halffacepiece

— PAPR A1 with half facepiece— Air-line with half facepiece

Final selection — Type A AUS or Type A1 gas filter with halffacepiece

Reason for choice The task is too short to merit selection of apowered respirator or supplied-air equipment

Replacement The filter should be replaced every week or soonerif the odour of MEK is apparent

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APPENDIX D

TYPICAL RESPIRATOR FIT TESTS

(Informative)

D1 GENERAL The proper fitting of respiratory protective equipment requires the useof some type of fit test to determine an adequate match between the facepiece of therespirator and face of the wearer.

D2 TEST METHODS

D2.1 Types There are two types of test—qualitative and quantitative. The use of oneor both types of test depends on the type of respirator to be fit tested, the extent ofrespirator usage and the available resources of trained personnel and capital. During anyfitting test, the respirator headstraps should be as comfortable as possible. Tightening thestraps will sometimes reduce facepiece leakage, but the wearer may be unable to tolerateusing the respirator for any length of time.

D2.2 Qualitative fit testing Qualitative tests are fast, require no complicatedexpensive equipment, and are easily performed. However, these tests rely on the wearer’ssubjective response, and so are not entirely reliable. There are three major (see ParagraphD2.3(a), (b) and (c)) and two minor (see Paragraph D2.4(a) and (b)) qualitative tests. Thefirst three use a test atmosphere which can be an enclosure into which—

(a) the user can enter wearing the equipment; and

(b) a ‘test’ contaminant (of low toxicity) can be placed.

Although elaborate enclosures are available commercially, the employer can put together a‘do-it-yourself’ qualitative fit test enclosure by the use of a plastic bag (a dry-cleaningbag), several hangers, and some cotton. Figure D1 shows a typical enclosure constructedusing these materials.

D2.3 Qualitative tests There are several qualitative tests including:

(a) Isoamyl acetate test Isoamyl acetate is a low toxicity substance with a banana-likeodour. It is only suitable for testing the face fit of respirators using organic vapourfilters. The substance is applied to the cotton wad inside the enclosure. Theprospective user should put on the respirator in an area away from the test enclosureso that there is no prior contamination of the filters by ‘pre-exposure’ to the isoamylacetate. The user shall enter the chamber and perform each of the followingactivities for 30 s:

(i) Normal breathing.

(ii) Deep breathing, to simulate heavy exertion. This should not be done longenough to cause hyperventilation.

(iii) Side-to-side and up-and-down head movements. These movements should beexaggerated, but should approximate those that take place on the job.

(iv) Talking. This is most easily accomplished by reading a prepared text loudlyenough to be understood by someone standing nearby.

(v) Other exercises may be added depending upon the situation. For example, ifthe wearer is going to spend a significant time bent over at some task, it maybe desirable to include an exercise approximating this bending.

The major drawback of the isoamyl acetate test is that the odour thresholdvaries widely among individuals. Furthermore, the sense of smell is easilydulled and may deteriorate during the test so the wearer can detect only high

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vapour concentrations. Another disadvantage is that isoamyl acetate smellspleasant, even in high concentrations. Therefore, a wearer may say therespirator fits although it has a large leak. This may be because the wearerlikes the fit of the particular respirator or is following the respirator selectionof someone else. Conversely, a wearer may claim that a particular respiratorleaks if it is uncomfortable. Therefore, unless the worker is highly motivatedtoward wearing respirators, the results of this test may sometimes be suspect.

(vi) Break respirator seal and expose wearer to test agent to verify the wearer’ssensitivity.

FIGURE D1 TYPICAL TEST ENCLOSURE

(b) Saccharin mist test This test is suitable for respirators incorporating anyparticulate filter. It relies upon the wearer’s ability to detect a saccharin aerosol bytaste. Individuals vary in their taste threshold, therefore a screening procedure isperformed to establish suitability.

Prospective test subjects are screened with an aerosol produced from a 0.83% byweight solution of sodium saccharin in water. The test subject remains inside thetest enclosure without a respirator and is instructed to breathe through the mouthonly. The solution is then puffed, up to 30 times, using a nebulizer through a holein the enclosure material. The number of puffs required for the subject to taste the

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saccharin is recorded. If the subject is unable to taste the saccharin after 30 puffs, adifferent method of testing facial fit should be used.

A period of at least several minutes should elapse after the sensitivity test beforere-testing the subject wearing a respirator.

The test subject, having passed the sensitivity test, is fitted with the appropriaterespirator. Since the saccharin mist is an airborne particulate, gas filter respiratorsshould be fitted with a particulate filter for the test. The subject is placed in the testenclosure and an aerosol produced from an 83% by weight solution of sodiumsaccharin in water is puffed through the hole. Initially, the number of puffs is thesame as the number taken to produce a response in the screening procedure. Halfthe number of puffs is delivered each 30 s. The test subject should performexercises such as those described in Paragraph D2.3(a). If the subject tastes thesaccharin, it is interpreted as a leakage of aerosol via the facial seal or throughrespirator component parts other than the filter or both.

This test suffers similar disadvantages to the isoamyl acetate test. Sweet food (orsweeteners, e.g. in coffee) should not be consumed 30 min prior to testing.

(c) Irritant smoke test This test uses an irritant smoke. It is only suitable for testingthe facial fit of air-supplied respirators or respirators incorporating P3 particulatefilters. The test substance is an irritant (stannic chloride or titanium tetrachloride)which is available commercially in sealed glass tubes. When the tube ends arebroken and air is passed through them (usually with a squeeze bulb), a denseirritating smoke is emitted. In this test, the user steps into the test enclosure and theirritant smoke is ‘sprayed’ into the test chamber. If the user detects any of theirritant smoke, it means a defective fit, and adjustment or replacement of therespirator is necessary. The irritant smoke test should be performed with cautionbecause the aerosol is highly irritating to the eyes, skin, and mucous membrane. Asa qualitative means of determining respirator fit, this test has the distinct advantagethat the wearer usually reacts involuntarily to leakage by coughing or sneezing. Thelikelihood of giving a false indication of proper fit is reduced.

D2.4 Quantitative tests Quantitative respirator performance tests involve placing thewearer in an atmosphere containing an easily detectable, relatively low toxicity gas,vapour, or aerosol. The atmosphere inside the respirator is sampled through a probe in therespirator. The leakage is expressed as the concentration inside the facepiece as apercentage of the outside concentration. The numbers generated by quantitative fit tests donot reflect the protection factors likely to be achieved in the workplace. The advantage ofa quantitative test is that it does not rely on a subjective response. However, these testsgenerally require equipment which can be operated only by highly trained personnel.Also, it can be difficult to use because of its complexity and bulk. Aerosol tests generallyuse particles much finer than those encountered in most industries and so requirerespirators with Class P3 particulate filters. Each test respirator should be equipped with asampling probe to allow removal of an air sample from the facepiece. Test facepieces maynot be worn in service, since the test orifice negates the approval of the respirator. Themost commonly available commercial quantitative tests are as follows:

(a) Sodium chloride (NaCl) test In this test, a liquid aerosol is generated continuouslyfrom a saltwater solution (using a nebulizer), dried to produce discretesub-micrometre salt particles, and dispersed into a test chamber or hood. A means isprovided for sampling the atmosphere in the chamber or hood and inside therespirator. These samples are fed to the detector section where the aerosol’spenetration inside the respirator is determined. The amount of penetration isdisplayed on a meter or recorder.

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(b) Oil mist test This test uses an air-generated oil mist. It differs from the NaCl testonly in that the aerosol particle is liquid. The aerosol is generated using a nozzleatomizer, but, being an oil, the mist does not dry into solid particles when injectedinto a diluting airstream.

(c) Particle counters In this test the natural dusts in the atmosphere are used as thetest aerosol.

D2.5 Fit checks These tests (negative pressure test and the positive pressure test)should be used only as a very gross determination of fit. The wearer should use these fitchecks just before entering the hazardous atmosphere. These tests are only suitable forrespirators with tight-fitting facepieces.

Although these tests are simple, they have severe drawbacks, the main one being that thewearer may handle the respirator after it has been positioned on the face, possiblymodifying the facial seal.

(a) Negative pressure fit checksThe following methods are suitable for negativepressure fit checks:

(i) Disposable respirators The wearer completely covers the filter with bothhands or a non-permeable substance, e.g. a polythene bag, and inhalessharply. The respirator may sink onto the face with a very vigorous breathindicating an adequate seal. If an unsatisfactory face seal is indicated by thefeel of an airstream channelling through the leak, re-adjust the respiratoruntil a satisfactory seal is indicated.

(ii) Rubber facepiece The user closes off the inlet of the filter or filters eitherby covering the intake or by squeezing the breathing tube so that it does notpass air, inhales gently so that the facepiece collapses slightly, and holds abreath for about 10 s. If the facepiece remains slightly collapsed and noinward leakage is detected, the respirator is probably well fitted.

(b) Positive pressure fit checksThe following tests are suitable only for close fittingrespirators:

(i) Disposable respirators (without exhalation valves)The wearer covers thefilter or filters either with both hands or a non-permeable substance, e.g. apolythene bag and exhales vigorously. If an unsatisfactory face seal isindicated by the feel of an airstream channelling through the leak, readjustthe respirator until a satisfactory seal is indicated.

(ii) Rubber facepiece The wearer closes off the exhalation valve and exhalesgently into the facepiece. The fit is considered satisfactory if slight positivepressure can be built up inside the facepiece without any evidence ofoutward leakage.

For some respirators, this check may require the wearer to remove the exhalationvalve cover which often disturbs the respirator fit even more than the negativepressure test. Therefore, this test should be used sparingly if it requires removingand replacing a valve cover. The test is easy for respirators which have a valvecover with a single small port that can be closed by the palm or a finger.

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FIGURE D2 NEGATIVE PRESSURE TEST

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APPENDIX E

FACIAL SEAL OF RESPIRATORS

(Normative)

E1 GENERAL Beard growth, some hairstyles and other facial features prevent anadequate seal between the wearer’s face and the fitting surfaces of a facepiece ormouthpiece. Facial hair may also interfere with inhalation and exhalation valve operation.Male wearers in particular shall be made aware of the general rules in Paragraphs E2to E6.

E2 BEARDS Bearded persons cannot expect to achieve adequate respiratory protectionwhen wearing a full facepiece respirator or a half facepiece respirator. Accordingly, noone who requires respiratory protection shall attempt to wear either a full facepiecerespirator or half facepiece respirator over a beard.

E3 MOUSTACHES Moustaches may spoil the fit of a half facepiece respirator andmay interfere with the peripheral seal of a full facepiece respirator. Moustaches should notprotrude beyond projected lines, drawn vertically from the corner of the mouth.

E4 SIDEBURNS When a full facepiece is being worn, sideburns shall not extendbelow a line drawn through the top of the tragion (the notch in the cartilage of the ear justabove and immediately in front of the earhole) and the canthus (corner) of the eye. Thisline is illustrated in Figure E1.

E5 STUBBLE GROWTH AND LONG HAIR Stubble growth, depending on itslength and stiffness, interferes to some degree with proper sealing of a facepiece and it isnecessary that male wearers of respirators shave daily.

When the hair is worn long, particular care should be taken to ensure that none is trappedbeneath the fitting surface.

E6 MOUTHPIECE AND NOSE CLIP A mouthpiece and nose clip may not provideadequate respiratory protection to a bearded person.

When the person at risk has a ‘bushy’ facial hairstyle, hair trapped between the lips andmouthpiece may prevent a satisfactory seal being obtained.

Because of the varying amount of cartilage in the noses of individuals, there is the addeddifficulty of obtaining a satisfactory seal of the nasal passages with a nose clip. Thisproblem is worsened by the presence of perspiration which may cause difficulty inmaintaining the nose clip in position.

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LEGEND:A = notch in the carti lage of the earB = canthus of the eyeC = line below which the sideburns should not extend

FIGURE E1 LENGTH OF SIDEBURNS

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APPENDIX F

EMPLOYEE TRAINING PROGRAM

(Informative)

F1 OUTLINE The format of this guide allows the instructor to adapt the trainingprogram to the individual requirements of the facility. This may be accomplished in thefollowing way:

(a) Where indicated, record the appropriate information for your facility, e.g. thelocations of operations where respirators are required, or where exposures toairborne contaminants necessitate the use of respirators.

(b) Refer to specific information in this Standard, for example, a discussion of thevarious types of respirator available (Section 6). Employees need not be aware of alltypes, but only those that they will be required to wear. Therefore, when the guideindicates that the information is to be inserted at that point in the presentation, onlythe relevant parts of this Standard need be utilized.

F2 FORMAT When planning the training session, remember that trainees usuallyretain only about 20% of what they hear, about 40% of what they see, and about 70% ofwhat they both see and hear. For the best results, therefore, a program of lectures,supplemented by audiovisual materials and demonstrations, is recommended. Thefollowing suggestions are made to help increase the effectiveness of the program.

(a) Cover the material suggested in the guide.

(b) Break the lecture into 30-45 minute intervals to allow the trainees to stand up andmove around.

(c) Use blackboard or overhead projector to emphasize subject sequence and majorpoints.

(d) Obtain slides or films from the National Safety Council, your trade association, orthe manufacturer/supplier of the equipment you use and intersperse them in thepresentation, as appropriate.

(e) Illustrate specific areas with personal experiences or examples related to youroperations.

(f) Have examples of the respirators used in your facility available during the trainingsession and highlight areas concerned with their operation and use.

(g) Supplement the material in this Standard with company operating procedures orinstructional material supplied by the equipment manufacturer/supplier.

F3 INSTRUCTIONS TO TRAINEES An integral part of the training program is thefree exchange of information—and questions—between instructor and trainees. Therefore,the following comments (made by the instructor) are suggested at the beginning of thetraining session:

‘During this session your full participation is needed.

(a) If you don’t understand what’s being discussed, ask questions.

(b) If you have been involved in or are aware of accidents pertaining to specific areascovered, share them with us.

(c) If you are aware of better approaches to reduce hazardous conditions, give us thebenefit of your experience.

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(d) Finally, if there is additional information or guidance we can provide, identify theareas for us.’

F4 EMPLOYEE TRAINING PROGRAM GUIDE

NOTES TO INSTRUCTOR SUGGESTED PROGRAM FORMAT

(a) Identification of the hazardBefore we getinto the ‘specifics’ about the respiratoryprotective equipment you will be hearing,a few s tatements about hazardidentification.

Discuss only those contaminantatmospheres representing problems inyour facility. See following discussion.

There are several kinds of hazardousatmosphere which may require the use ofa respirator.

(i) Gaseous contaminantsGases are thenormal form of substances likecarbon dioxide or hydrogen sulfide.These substances are solids orliquids only at very low temperaturesor extremely high pressures. Carbondioxide, for instance, is a gas atroom temperature. But it also occursas solid ‘dry ice’ formed at lowtemperatures.

(ii) Particulate contaminants Particu-lates are tiny particles, solid orliquid, generated by such processesas grinding, crushing, and mixing ofa compound, either a solid or aliquid. There are three types ofparticulate.

Dusts are solid particles produced bysuch processes as grinding, crushing,and mixing of powder compounds.Examples are sand and plaster dust.By comparison with the followingtwo types of particulates, dustparticles are usually large.

Mists are tiny liquid droplets, usuallyformed whenever a liquid is sprayed,vigorously mixed, or otherwiseagitated. Acid mists around diptanksused for metal cleaning, and oilmists near newspaper printingpresses are two examples.

Fumes are solid condensationparticles of extremely small size.Fumes are found in the air nearsoldering, welding, and brazingoperations, as well as near moltenmetal processes such as casting andgalvanizing.

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The two basic forms—gases andpar ticulates—f requent ly occurtogether. Paint spraying operations,for example, produce both paint mist(particulates) and solvent vapours(gases).

A further discussion of ODAs can befound in Section 3.

O xygen- de f ic ient a tmospher es(ODAs) are most commonly found inconfined spaces which have poorventilation. Examples are silos,petrochemical tanks, degreasers, andthe holds of ships.

(b) Reasons for respirators

(i) State regulatory authorities Thesehave set maximum exposurestandards for many airborne toxicmaterials and have set standardsgoverning specific working environ-ments to protect your health. Arecent evaluation of your workingenvironment revealed that:

Name work area (1)List substances (2)

(A) In work areas (1), atmosphericconcentrations of substances (2)were found to be aboveacceptable limits.

Describe activities (1)Describe exposure (2)

(B) During maintenance activities(1) you are exposed to (2) a highconcentration for a short periodof time. This will lead toexcessive exposure.

Describe areas (1) (C) Several areas (1) were found tobe ‘oxygen deficient’.

Name storage areas (1)Describe emergency situation whichcould exist in your plant (2)

(D) Hazardous substances are storedat (1) and if these substancesspill or leak, an emergencycondition may exist, for example(2).

Suggested phraseology (ii) Status of engineering controlsSince the company recognizesthat respiratory protection is notthe primary method for controlof airborne hazards, we aretaking steps to implementengineering control solutions.

Describe what controls are beingimplemented (1)

(A) We will install the followingengineering controls (1).

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Discuss administrative schedules, e.g.rotating work controls, spreading workover two shifts, job rotation (2).

(B) And the following administrativecontrols (2).

However, while the above stepsa r e be in g i m pl em e n t e d,respiratory protection will berequired.

(c) Respirator selection Selection of theproper equipment normally involves threesteps: the identification of the hazard; theevaluation of the hazard; and finally theselection of the appropriate respiratoryequipment based on the first two steps:

After explaining to the employee thetype of hazardous atmosphererequiring respiratory protection, youshould then discuss the specifichazards. Check vendor literature,toxicologic references, or materialsafety data sheet.

(i) H azard spec if icat ions Theseinclude—

(A) hazard name—

—organic vapour (name);

—particulate (name); or

—gas (name).

(B) toxicity data and effects.

Refer to Section 4 (ii) Evaluation of the hazard Todetermine the concentration of thehazard, as identif ied above,measurements were made. Theconcentrations in the work environ-ment examined were compared withthe relevant WorkSafe and AustralianStandards.

(iii) Selection of the respirator Afterit was determined that respiratorswere required, this Standard(AS/NZS 1715) was consulted tofind out the appropriate respirator.

(d) Use and proper fitting of respirators Apoor facial seal can cause contaminants tobe inhaled through the respiratory sealingsurfaces, instead of through the filters, orair supply system.

Using Appendix E and informationsupplied by the manufacturer, show theemployee how to put on the selectedr espi ra tor . S how the var iouscomponent parts of the respirator, andhow the respirator functions to removethe contaminants.

(i) Use of respiratory protectiveequipment So that respirators usingt ight - f i t t ing f acepieces givemaximum protection, it is mostimportant to ensure a proper ‘match’between the facepiece and your face.

(ii) Proper fitting

At this time, you should have availableat least two different types (fromdifferent manufacturers) of respiratoryequipment for the employee to try on.

(A) In most cases, there are severaldifferent brands of the same typeof r espi r a tor y equipmentapproved for use against aspecific hazard.

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Refer to Appendix D for discussion offitting tests.

(B) However, just because arespirator ‘feels comfortable’ itdoes not mean it is protectingyou to the fullest extent from thehazard. The key word is properfit. To determine if the fit isproper, several tests can be used.Each facepiece may be availablein different sizes.

(e) Wear time The importance of wearingthe respirator at all times the user is inthe contaminated area must beemphasized.

Refer to Section 6 for factors inse lec t ion w hich includes uselimitations.

(f) Limitations of respirators The respira-tory equipment you will use does havesome limitations affecting its use.

(g) Maintenance and storage of respiratorsTo ensure the continued properfunctioning of respirators, they must beregularly cleaned and disinfected, andstored in a convenient and clean location.

Refer to Section 7 for detailsconcerning the cleaning of equipment.Several suggested cleaning methodsare given. Discuss provisions.

(i) Cleaning Your respirator shall becleaned daily after use. The companyhas made provisions for doing this.

Refer to Section 7 and discuss storageprovisions by company.

(ii) Storage Equipment should bestored properly at the conclusion ofthe work shift.

Refer to Section 7 for discussion aboutinspecting equipment for defects.

(iii) Inspection for defects This is oneof the most important functionsassociated with respirator usage.These inspections can identifyproblems with malfunctioningrespirators.

Refer to Clause 7.7.3. (iv) Record keeping.

Before you discuss this Section withthe user, you should first prepare thesummary—as it applies to your usage.

(h) Summary A summary of the respiratorprogram. Reasons for respirators.

(i) Respirator selection procedure:

(A) Identification of hazard.

(B) Hazard specification.

(C) Evaluation of the hazard.

(D) Selection of the respirator.

(ii) Proper fitting and usage:

(A) Fitting.

(B) Use.

(iii) Limitations

(iv) Maintenance and storage

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APPENDIX G

TYPICAL METHOD OF MEASURING VALVE LEAKAGE

(Informative)

G1 LEAKAGE METER The leakage meter (Figure G1) consists of a cylindricalvessel approximately 125 mm diameter× 250 mm high, the open end of which is closedby a metal plate and a rubber gasket. Tube A connects the apparatus to a vacuum line andis fitted with a valve to control the rate of flow. Tube B is open to air and the depth ofinsertion within the glass vessel can be varied by a simple gland. The component undertest is attached to tube C which has a gland which allows axial movement at a constantdepth. The end of tube C is bent so that it can be positioned centrally under the 30 mLglass measuring vessel which is attached to the air release tap (D) by a rubber sleeve.

G2 USE OF METER To prepare the meter for use, the glass vessel is filled withwater to the zero mark on the 30 mL measuring vessel. Tube C is closed and suction isapplied to the meter through tube A. Bubbles will rise from the bottom of tube B and thevalve in the suction line is adjusted until the flow rate is approximately 60 to 80 bubblesper min. A manometer is attached to tube C and the depth of tube B is adjusted until thepressure in tube C is 25 mm of water.

In operation the component under test is attached to tube C by a suitable jig or connectionand the tube is removed from under the measuring vessel. The air release tap (D) isopened to allow air to escape from the measuring vessel and then closed. When conditionsare steady, the end of tube C is moved under the measuring vessel and the time taken forthe leakage to fill the measuring vessel to the 30 mL mark is noted.

Valve assemblies can usually be testedin situ and can be connected to the leakage meterby simple jigs which may be fashioned from laboratory grade rubber stoppers.

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FIGURE G1 LEAKAGE METER

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APPENDIX H

COMPRESSED BREATHING AIR FILTRATION SYSTEMS

(Informative)

H1 SCOPE This Appendix provides information for the purchaser of compressedbreathing air filtration systems covering the basic features of a filtration system foroil-lubricated compressors designed to deliver pure, dry, respirable air to the user.

H2 COMPRESSOR LOCATION Since compressed breathing air is a processedproduct, the filtration system should be capable of eliminating harmful matter to producea suitable end-product. This initially requires that the compressor be correctly mountedand located in an area providing ample space on all sides to ensure good ventilation andmaintenance accessibility. The compressor should also be placed in an area where theambient temperature is as cool as possible. The air intake should be located in open air,away from any source of atmospheric contamination. The use of filters on an air intakeshould be of secondary importance to this requirement. The possibility of contaminationof the compressor intake by discharge from pressure relieving devices on other plant inthe vicinity should be considered as well as the effects of changes in wind direction. Aparticular problem may be presented where the compressor is driven by an internalcombustion engine or is located close to motor vehicles.

H3 AIR PURIFICATION ELEMENTS The effectiveness of the air purification trainrequires that the elements comprising the system be placed in the correct sequence (seeFigure H1). The first element in the purification system is a mechanical device to removeliquid water. The air, after leaving the mechanical water separator, passes into acoalescing filter or equivalent where oil, aerosol and submicron particles are removed. Anair dryer or sorbent filter then reduces the water vapour content of the compressed air toprevent moisture contamination of the next stage, an activated charcoal filter designed toremove oil, odours and some organic and hydrocarbon vapours. If the carbon dioxidecontent of the compressed air needs to be reduced, an additional sorbent filter may berequired. The next step in the purification process may be the catalytic conversion ofcarbon monoxide to carbon dioxide. In some instances, where the carbon monoxideconcentration is high, it may be necessary to reverse the sequence of these last two stages.A dust filter may then be required to protect the air delivery system from disintegratedpurification media.

NOTE: Some purifiers are designed to remove a number of contaminants in one vessel.

H4 PERFORMANCE CRITERIA When writing specifications for an air purificationpackage, the user should state that when installed in the user’s premises, the system shallproduce air which meets the air quality requirements of Appendix A of this Standard for aspecified period of time at a specified air flow rate.

H5 MAINTENANCE A record of the periodic replacement of the filter media shouldbe maintained in accordance with the manufacturer’s instructions and specifications.

H6 AIR PURIFICATION TRAIN This system will comprise a number of pressurevessels that should be designed and approved in accordance with AS 1210.

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NOTE: Not all purification elements may be required.

FIGURE H1 SEQUENCE OF A TYPICAL BREATHING AIR-LINEPURIFICATION TRAIN

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APPENDIX I

TYPICAL METHOD OF MEASURING INHALATION ANDEXHALATION RESISTANCE

(Informative)

I1 RESISTANCE METER Typically, a resistance meter for measuring both negativeand positive pressure consists of a control valve, an air flowmeter, a manometer and ameasuring tube for connection to the component under test.

I2 APPARATUS A typical arrangement of the apparatus is shown in Figure I1. Themeasuring tube should have an internal diameter of not less than 22 mm and themanometer should be arranged so that true static pressure within the measuring tube isindicated by the manometer. The respirator component to be tested is connected to themeasuring tube. Some form of simple jig may be necessary to facilitate the connection ofthe component to the resistance meter.

I3 PROCEDURE The air flow is set at the required rate by means of the control valveand the ‘zero’ setting on the manometer adjusted prior to connecting the component undertest.

When a jig is used this should be connected to the measuring tube without the componentunder test and if necessary the flowrate and manometer readjusted before connecting thecomponent under test.

The resistance value is then read from the manometer.

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(a) Suction

(b) Pressure

* 1500 Pa = 150 mm H2O

FIGURE I1 RESISTANCE METER —TYPICAL ARRANGEMENT

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APPENDIX J

CHECKPOINTS FOR RESPIRATOR PROGRAMADMINISTRATION AND OPERATION

(Informative)

J1 PROGRAM ADMINISTRATION Program responsibility should be given tosomeone who is knowledgeable about respirators and who can coordinate all aspects ofthe program.

The coordinator should know the present status of the implementation of engineeringcontrols, if feasible, to alleviate the need of respirators.

The coordinator should ensure that there are written procedures/statements covering suchaspects of the respirator program as—

(a) designation of administrator;

(b) respirator selection;

(c) purchase of approved equipment;

(d) medical screening of respirator users;

(e) record keeping;

(f) issue of equipment;

(g) fitting;

(h) disinfection, cleaning, storage, inspection, repair;

(i) training in proper selection and usage;

(j) use under special conditions, i.e. confined spaces, escape and atmospheresimmediately dangerous to life or health; and

(k) audit program for effectiveness and ensure that corrective action is undertaken whennecessary.

J2 PROGRAM OPERATION Checks should be carried out to ensure adherence tothe following matters:

(a) Respirator selection Users must ensure the following:

(i) Work area conditions and employee exposures are properly surveyed.

(ii) Respirators are selected on the basis of hazards to which the employee isexposed.

(iii) Selections are made by individuals knowledgeable about selectionprocedures.

(iv) Only approved respirators which provide adequate protection for the specifichazard and concentration of the contaminant are purchased and used.

(v) Medical evaluation of the prospective users has been made to determine theirphysical and psychological suitability to wear respiratory protectiveequipment.

(vi) Where respirators have been issued to the users for their exclusive use,records covering the issue of these respirators are maintained.

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(b) Respirator fitting

(i) Users are given the opportunity to try on several respirators to determinewhether the respirator they will subsequently be wearing is the best fittingone.

(ii) The respirator is fit tested at appropriate intervals, with an appropriate test.Records of such tests are maintained.

(iii) Those users who require corrective lenses are properly fitted.

(iv) Wearers check the fit of their respirators each time they are donned.

(c) Cleaning and disinfecting

(i) Respirators are cleaned and disinfected after each use when different peopleuse the same device, or as frequently as necessary for devices issued toindividual users.

(ii) Proper methods of cleaning and disinfecting are utilized.

(d) Storage

(i) Respirators are stored so as to protect them from dust, sunlight, heat,excessive cold or moisture, or damaging substances.

(ii) Respirators are stored properly in a storage facility to prevent deformation.

(iii) Storage in lockers and tool boxes is permitted only if the respirator is in acarrying case or carton.

(iv) Gas and vapour filters are stored in containers/bags with airtight seals.

(v) Respirators are stored close to where they will be used.

(e) Inspection

(i) Respirators are inspected before and after each use and during cleaning.

(ii) Qualified individuals/users are instructed in inspection techniques.

(iii) Respiratory protective equipment designated for ‘emergency use’ is inspectedat least monthly (as well as after each use).

(iv) A record is kept of the inspection of ‘emergency use’ respiratory protectiveequipment.

(f) Repair

(i) Replacement parts used in repair are those of the manufacturer of therespirator.

(ii) Repairs are made by individuals knowledgeable about respirators.

(iii) Repairs of SCBA are made only by certified personnel or by amanufacturer’s representative.

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INDEX

AbsorptionFilter capacity . . . . . . . . . . . . . . . . . . . . . . . . 5.3.3.3General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1Ingestion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.4Inhalation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2Through skin . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.3

AcceptanceUser . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.4.4

Acid gasesFilter selection . . . . . . . . . . . . . 5.3.3, 6.2.4, Table 6.4Filter types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.3.3

Additional protectionGoggles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.2.7.2Head coverings . . . . . . . . . . . . . . . . . . . . . . . . 6.2.7.3Spectacles . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.2.7.2

Advisory authoritiesListing . . . . . . . . . . . . . . . . . . . . . . . . . . . Appendix B

Air blowerElectrical . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.4.4.3Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.4.4.2

Air-hoseHigh temperature use of . . . . . . . . . . . . . . . . . . . 7.9.6Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.8.4.3Limiting distance . . . . . . . . . . . . . . . . . . . . . . . . 6.3.4Respirator

categories . . . . . . . . . . . . . . . . . . . . . . . 5.4.2, 5.4.4definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.5.2

Use of . . . . . . . . . . . . . . . . . . . . . . . . . 6.2.3.6, 7.9.6Air-line

High temperature use of . . . . . . . . . . . . . . . . . . . 7.9.6Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.8.4.3Limiting distance . . . . . . . . . . . . . . . . . . . . . . . . 6.3.4Negative pressure . . . . . . . . . . . . . . . . . . . . . . 6.2.4.4Respirator

categories . . . . . . . . . . . . . . . . . . . . . . . 5.4.2, 5.4.5definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.5.3

Use of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.2.3.6Air quality

Filtration requirements . . . . . . . . . . . . . . . Appendix HRequirements

cylinders . . . . . . . . . . . . . . . . . . . . . . . . Appendix Acompressors . . . . . . . . . . . . . . . . . . . . . Appendix A

System inspection . . . . . . . . . . . . . . . . . . . . . . 4.3, 7.8Air sampling seeMonitoringAir temperature

High . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.9.5.2Low . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.9.5.1Requirements . . . . . . . . . . . . . . . . . 5.4.1, Appendix A

AmmoniaEffects of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2.2Filter selection . . . . . . . . . . . . . . . . . . 5.3.3, Table 6.4Indication . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.2.8.2

AnaestheticsEffects of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2.2

Approved equipmentManagement responsibility . . . . . . . . . . . . . . . . . . . 7.1Purchase of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.2

AsbestosExposure standard . . . . . . . . . . . . . . . . . . . . . . . . 4.2.2

Filter for . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.3.2Filter selection . . . . . . . . . . . . . . . . . 6.2.3.3, Table 6.1Hazard evaluation . . . . . . . . . . . . . . . . . . . . . . . . 4.2.2Inhalation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2.3

AsphyxiantsEffects of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2.2

AtmosphereComposition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.2Oxygen deficiency . . . . . . . . . . . . . . . . . . . . . . . . 3.3

Auxiliary protectionEscape type . . . . . . . . . . . . . . . . . . . . . . . . . . 5.4.7.1Filter type . . . . . . . . . . . . . . . . . . . . . 5.4.7.1, 5.4.7.2General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.4.7.1Low air warning . . . . . . . . . . . . . . . . . 5.4.7.1, 5.4.7.3

Banana oilseeIsoamyl acetateBatteries

Care of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.8.6Recharging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.8.6

BeardsseeHairBody entry

Ingestion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.4Inhalation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2Skin absorption . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.3Skin penetration . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1

deep wounds . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1Breathing

In aircraft . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.1Underwater . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.1

Breathing airAuxiliary protection . . . . . . . . . . . . . . . . . . . . . . 5.4.7Continuous flow . . . . . . . . . . . . . . . . . . . . . . . 5.4.3(b)Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.5.6Filtration . . . . . . . . . . . . . . . . . . . . . 5.3, Appendix HGeneral . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.1, 5.4.1Mode of delivery . . . . . . . . . . . . . . . . . . . . . . . . 5.4.3Natural breathing . . . . . . . . . . . . . . . . . . . . . . 5.4.3(a)

definition . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.5.32Negative pressure demand . . . . . . . . . . . . . . . . 5.4.3(c)Positive pressure demand . . . . . . . . . . . . . . . . . 5.4.3(d)Provision of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.1Self contained . . . . . . . . . . . . . . . . . . . . . . . . . . 5.4.6Supplied . . . . . . . . . . . . . . . . . . . . . . . . . . 5.4, 5.4.2

Breathing resistanceAir hose . . . . . . . . . . . . . . . . . . . . . . . . . . 5.4.4.2, 6.1Filter replacement . . . . . . . . . . . . . . . . . . . . . . . . 7.10

CanisterseeFilterCartridgeseeFilterClassifications

Air-purifying respirator . . . . . . . . . . . . . . . . . . . . . 5.3Gas filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.3.3Hazard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.1.2Particulate filter . . . . . . . . . . . . . . . . . . . . . . . . . 5.3.2

CleaningGeneral . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.6.1Sanitizing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.6.2

Coarse particulate filterseeFilter

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Combined hazardsProtection against . . . . . . . . . . . . . . . . . . . . . . . . 6.2.5

CommunicationIn flammable or explosive

atmospheres . . . . . . . . . . . . . . . . . . . . . . . . . . 6.2.9Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.3.5Speech transmission devices . . . . . . . . . . . . . . . . 7.9.3

Confined spacesEntry to . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.9.4Safe procedures . . . . . . . . . . . . . . . . . . . . . . . . . . 3.1

ConsiderationsPhysiological . . . . . . . . . . . . . . . . . . . . . . 6.4.2, 7.3.1Psychological . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.3.1

ContaminantAtmospheric definition . . . . . . . . . . . . . . . . . . . . 1.5.5Concentration . . . . . . . . . . . . . . . . . . . . . . . . . 6.2.2.3Protection against . . . . . . . . . . . . . . . . . . . . . . . . . 6.2Warning by . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.2.8

Cylinders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.4, 5.6

Deep wounds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1Demand valveseevalvesDust seeParticulates

Emergency locations . . . . . . . . . . . . . . . . . . . . . . . 7.6.3Equipment

Management responsibility . . . . . . . . . . . . . . . . . . . 7.1Purchase of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.2Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.6, 7.6.3

Explosive atmospheresRespirators in . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.2.9

Exposure standards . . . . . . . . . . . . . . . 1.3, 4.2.2, 6.2.2.2Eye correctionsee alsoVision

In respirators . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.5.4

Facial sealFacial hair, effect of . . . . . . . . . . . . 7.5.3, Appendix DFit check definition . . . . . . . . . . . . . . . . . . . . . . 1.5.13Fit test definition . . . . . . . . . . . . . . . . . . . . . . . 1.5.14Fit test frequency . . . . . . . . . . . . . . . . . . . . . . . . 7.5.2Importance of . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.4.3Tests . . . . . . . . . . . . . . . . . . . . . . . . 7.5, Appendix D

FiltersCapacity (see alsoClassification) . . . . . . . . . . . 5.3.3.3Classification . . . . . . . . . . . . . . . . . . . . . . 5.3, 6.2.3.2Combination definition . . . . . . . . . . . . . . . . . . . . 1.5.8Combination gas and particulate . . . . . . . . 5.3.4, 7.10.4Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.5.15External . . . . . . . . . . . . . . . . . . . . . . . . . 5.3.4, 7.10.4Frequency and length of usage . . . . . . . . . . . . . . . 6.3.2Gas classification . . . . . . . . . . . . . . . . . . . . . . 5.3.3.3Gas life of . . . . . . . . . . . . . . . . . . . . . . . . . . 6.2.4.3Gas types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.3.3Particulate classification . . . . . . . . . . . . . . . . . . . 5.3.2Pre-filter . . . . . . . . . . . . . . . . . . . . . . . . 5.3.4, 7.10.4Self-rescue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.3.5Self-rescuer (industrial) . . . . . . . . . . . . . . . . . . 5.3.5.4Self-rescuer (mines) . . . . . . . . . . . . . . . . 5.3.5.2, 7.8.5Types . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.2, 5.4.7.2

Fit checksFacial seal . . . . . . . . . . . . . . . . 7.5.2, Appendices D, ENegative pressure . . . . . . . . . . . . . 7.5, Appendix D2.5Positive pressure . . . . . . . . . . . . . . 7.5, Appendix D2.5

Fit testsBefore issue . . . . . . . . . . . . . . . 7.5.2, Appendices D, EFacial . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.5Frequency of . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.5.2Qualitative (definition) . . . . . . . . . . . . . . . . . . . 1.5.44Quantitative (definition) . . . . . . . . . . . . . . . . . . 1.5.45

Flammable atmospheresRespirators in . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.2.9

FumeDefinition . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.5.18Filter selection . . . . . . . . . . . . . . . . . . . . . . Section 6Inhalation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2.2

Gas filter seeFiltersGases

Acid inhalation of . . . . . . . . . . . . . . . . . . . . . . . . 2.2.2Organic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.3.3Toxic (protection against) . . . . . . . . . . . . . . . . . . 6.2.4

GogglesUse of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.2.7.2

HairFacial (beards) . . . . . . . . . . . . . 6.4, 7.5.3, Appendix ELong . . . . . . . . . . . . . . . . . . . 6.4.3, 7.5.3, Appendix EMoustaches . . . . . . . . . . . . . . 6.4.3, 7.5.3, Appendix ESideburns . . . . . . . . . . . . . . . . . . . . . . . . . Appendix E

Harmful substances . . . . . . . . . . . . . . . . . . . . Section 2Hazard

Classification . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.1.2Combined, protection . . . . . . . . . . . . . . . . . . . . . 6.2.5Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.3Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2Exposure standards . . . . . . . . . . . . . . . . . . . . . . . 4.2.2Isolation of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.3Recognition of . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.1

Head coveringsUse of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.2.7.3

HosesseeAir-hoseseeAir-line

Ingestion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.4Inhalation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2Inspection (equipment)

see alsoCleaningand Maintenance . . . . . . . . . . . . 7.6Consideration . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.8For defects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.7Record keeping . . . . . . . . . . . . . . . . . . . . . . . . . . 7.7.3Requirements . . . . . . . . . . . . . . . . . . . . . . . 7.6, 7.7.2Schedules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.7.2

IrritantsGases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2.2(a)Particulates . . . . . . . . . . . . . . . . . . . 2.2.4(a), 2.2.4(c)

Isoamyl acetate . . . . . . . . . . . . . . . . . . . . . . Appendix DIsolation

of hazard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.3Issue

of respirators . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.4Record keeping . . . . . . . . . . . . . . . . . . . . . . . . . . 7.7.3

LifeGas filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.2.4.3

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LungDamage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2.3

MaintenanceCleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.6Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.8Periodic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.6.4Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.6Record keeping . . . . . . . . . . . . . . . . . . . . . . . . . . 7.7.3Respirator . . . . . . . . . . . . . . . . . . . . . 6.3.6, 7.4, 7.6.4

ManagementResponsibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.1

MaskSmoke . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.3.5.3

Material safety dataSheets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.1.1

Medical screening . . . . . . . . . . . . . . . . . . . . . . . . . . 7.3Mercury

Filter selection . . . . . . . . . . . . . . . . Tables 6.3 and 6.4Methyl bromide . . . . . . . . . . . . . . . . . Tables 6.3 and 6.4Mobility

Degree of activity . . . . . . . . . . . . . . . . . . . . . . . . 6.3.3Respirator selection . . . . . . . . . . . . . . . . . . . . . 6.2.3.6

MonitoringBiological . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2.1(c)Contaminant concentration . . . . . . . . . . . . . . . . . 7.11.2Environmental . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2.1General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2.1Hazard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2.1Personal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2.1(a)

MoustachesseeHairMouthpiecesee alsoNose clip

Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.5.31Lack of sealing . . . . . . . . . . . . . . . . . . . . . Appendix E

Negative pressureDemand . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.4.3(c)Fit test . . . . . . . . . . . . . . . . . . . . . . . 7.5, Appendix D

Nose clipsee alsoMouthpieceDefinition . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.5.34Lack of sealing . . . . . . . . . . . . . . . . . . . . . Appendix E

Occupational Hygienistdefinition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.5.36

Occupational Hygienedefinition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.5.35

OdourWarning properties . . . . . . . . . . . . . . . . . . . . . 6.2.8.1

OxygenCompressed supply . . . . . . . . . . . . . . . 5.4.6.3, 5.4.6.4

requirements . . . . . . . . . . . . . . . . . . . . . Appendix ADeficiency . . . . . . . . . Section 3, Table 6.6, 7.9.1, 7.9.4Deficiency —Protection against . . . . . . . . . . . . . . 6.2.6Generating apparatus . . . . . . . . . . . . . . . . . . . . 5.4.6.6Liquid supply . . . . . . . . . . . . . . . . . . . . . . . . . 5.4.6.5

ParticulatesBody entry . . . . . . . . . . . . . . . . . . . . . . . . . 2.2.3, 2.4Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.5.39Fever producing . . . . . . . . . . . . . . . . . . . . . . . 2.2.4(d)Inhalation of . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2.3Irritant . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2.4(c)Lung damaging . . . . . . . . . . . . . . . . . . . . . . . . 2.2.4(b)

Nuisance . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2.4(a)Protection against . . . . . . . . . . . . . . . . . . . . . . . . 6.2.3Thermally generated . . . . . . . . . . . . . . . . . . Table 6.2

Performance, factors effectingseeMedical screening 7.3.2Physiological considerations

Basic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.4.2Medical screening . . . . . . . . . . . . . . . . . . . . . . . . 7.3.Respirator selection . . . . . . . . . . . . . . . . . . . Section 6

PoisonsGaseous . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2.2Particulates . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2.3Systemic . . . . . . . . . . . . . . . . . . . . . 2.2.2(c), 2.2.4(e)

Positive pressureDemand . . . . . . . . . . . . . . . . . . . 5.4.3(d), Appendix CFit test . . . . . . . . . . . . . . . . . . . . . . . 7.5, Appendix C

Pre-filter seeFiltersProgram

Effectiveness . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.11Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.11.3

Protection factorDefinition . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.5.43Determination of . . . . . . . . . . . . . . . . . . . . . . . 6.2.2.2Exposure standard . . . . . . . . . . . . . . . . . . . . . . 6.2.2.2Frequency of use . . . . . . . . . . . . . . . . . . . . . . . . 6.2.3Gas filter respirator . . . . . . . . . . . . . . . . . . . . . 6.2.4.2Length of use . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.3.2

Psychological considerations . . . . . . . . . . . . . . . . . . 7.3.1

RecordsInspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.7.3Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.7.3of issue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.7.3

RepairseeMaintenanceReplacement

Components,seeSubstitutionof filters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.10

Respirable airseeBreathing airRespirator

Air-purifying . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.3Air-hose, types of . . . . . . . . . . . . . . . . . . . . . . . . 5.4.4Air-hose, use of . . . . . . . . . . . . . . . . . . . 6.2.3.6, 7.9.6Air-hose, types of . . . . . . . . . . . . . . . . . . . . . . . . 5.4.5Air-line, use of . . . . . . . . . . . . . . . . . . . . 6.2.3.6, 7.9.6Auxiliary protection . . . . . . . . . . . . . . . . . . . . . . 5.4.7Chemical oxygen . . . . . . . . . . . . . . . . 5.4.6.1, 5.4.6.6Combination filter definition . . . . . . . . . . . . . . . . 1.5.8Compressed air types

seeSelf containedseeSCBA

Consideration for maintenance . . . . . . . . . . . . . . . . 7.8Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.5.50Effectiveness . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.11Escape type . . . . . . . . . . . . . . . . . . . . . . . . . . 5.4.7.2Eye correction . . . . . . . . . . . . . . . . . . . . . . . . . . 7.5.4Filter replacement . . . . . . . . . . . . . . . . . . . . . . . . 7.10Frequency of use . . . . . . . . . . . . . . . . . . . . . . . . 6.3.2Inspection of . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.7Issue of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.4Length of use . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.3.2Life support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.1Liquid oxygen . . . . . . . . . . . . . . . . . . . . . . . . 5.4.6.5Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.6.4Non-powered . . . . . . . . . . . . . . . . . . . . . . . . . 5.3.1(a)

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Oxygen generating . . . . . . . . . . . . . . . 5.4.6.1, 5.4.6.6Particulate . . . . . . . . . . . . . . . . . . . . . . . 5.3.1, 7.10.2Powered . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.3.1(b)Selection . . . . . . . . . . . . . . . . . . . . . . . . . . Section 6Selection factors . . . . . . . . . . . . . . . . . . . . . . . 6.3, 6.4Self contained breathing types (SCBA) . . . . . . . . . 5.4.6Self-rescuer

Industrial . . . . . . . . . . . . . . . . . . . . . . . . . . 5.3.5.4Mines . . . . . . . . . . . . . . . . . . . . . . . . . 5.3.5.2, 7.8.5Smoke mask . . . . . . . . . . . . . . . . . . . . . . . . 5.3.5.3

Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.6.3Supplied air . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.4

Categories . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.4.2When required . . . . . . . . . . . . . . . . . . . . . . . 6.2.4.4

Training . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.12Types of . . . . . . . . . . . . . . . . . . . . . . . . . Section 5Use in flammable or explosive atmospheres . . . . 6.2.9User acceptance . . . . . . . . . . . . . . . . . . . . . . . . 6.4.4

Safe working practicesCommunication . . . . . . . . . . . . . . . . . . . . . . . . . 7.9.3Confined spaces . . . . . . . . . . . . . . . . . . . . . . . . . 7.9.4General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.9.1

SCBAAuxiliary protection . . . . . . . . . . . . . . . . . . . . . . 5.4.7Batteries, care of . . . . . . . . . . . . . . . . . . . . . . . . 7.8.6Cleaning general . . . . . . . . . . . . . . . . . . . . . . . . . . 7.6Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.5.51General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.4.6.1Inspection . . . . . . . . . . . . . . . . . . . . . . . . 7.8, 7.8.4.4Issue of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.4Maintenance . . . . . . . . . . . . . . . . . . . . . . . . 7.6.4, 7.8Sanitizing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.6.2Screening of users . . . . . . . . . . . . . . . . . . . . . . . . . 7.3Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.6.3Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.4.6

Screening of usersMedical . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.3Physiological considerations . . . . . . . . . 6.4.2, 7.3.1(a)Psychological considerations . . . . . . . . . . . . . . 7.3.1(b)

Selection factors . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.1Contaminant-related . . . . . . . . . . . . . . . . . . . . . . . 6.2Operator-related . . . . . . . . . . . . . . . . . . . . . . . . . . 6.4Task-related . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.3

Self rescueseeRespirators—Self-rescuer

Sensitizing agents . . . . . . . . . . . . . . . . 2.2.2(e), 2.2.3(f)Servicing

Cleaning and maintenance . . . . . . . . . . . . . . . . . . . 7.6Consideration . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.8Cylinder valves . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.3Exhalation valves . . . . . . . . . . . . . . . . . . . . . . . . . 8.2Facepieces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.2Filter replacement . . . . . . . . . . . . . . . . . . . . . . . . 7.10Inspection for defects . . . . . . . . . . . . . . . . . . . . . . 7.7Other components . . . . . . . . . . . . . . . . . . . . . . . . . 8.3SCBA components . . . . . . . . . . . . . . . . . . . . . . . . 8.3

SideburnsseehairSkin absorptionseeAbsorptionSmoke

Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.5.55Irritant test . . . . . . . . . . . . . . . . . . Appendix C2.1.1(c)

Smoke mask . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.3.5.3Sodium chloride test . . . . . . . . . . . . . Appendix D2.4(a)Sorbent

Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.5.56SpectaclesseeEye correction

Use of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.2.7.2Speech transmissionseeCommunicationStorage

Of batteries . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.8.6Of cylinders . . . . . . . . . . . . . . . . . . . . . . . . 7.6.3, 8.3Of equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.6.3Provision of . . . . . . . . . . . . . . . . . . . . . . . . 7.1, 7.6.1Self-rescuer (mines) . . . . . . . . . . . . . . . . . . . . . . 7.8.5

Stubble growthseeHairSubstitution

Hazard reduction . . . . . . . . . . . . . . . . . . . . . . . . . 4.3Of components . . . . . . . . . . . . . . . . . . . . . . . . . . 7.6.4

Systemic poisonsseepoisons

TemperatureHigh temperature, hoses, use of . . . . . . . . . . . . 7.9.5.2Low temperature, hoses, use of . . . . . . . . . . . . 7.9.5.1Respirators, usage

Toxic gasseeGasesTraining

Employee program . . . . . . . . . . . . . . . . . . Appendix FManagement responsibility . . . . . . . . . . . . . . . . . . . 7.1Respirator usage . . . . . . . . . . . . . . . . . . . . . . . . . 7.12

UsageFrequency of . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.3.2Length . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.3.2

ValvesInhalation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.2Exhalation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.2Demand . . . . . . . . . . . . . . . . . . . . . . 5.4.3(c), 5.4.3(d)Inhalation, or exhalation . . . . . . . . . . 5.4.3(c), 5.4.3(d)Leakage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.8.3.3Servicing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.2

VentilationHazard control . . . . . . . . . . . . . . . . . . . . . . . . . 4.3(c)

VisibilitySelection factors . . . . . . . . . . . . . . . . . . . . . 6.3, 6.3.5

VisionCorrective lenses . . . . . . . . . . . . . . . . . . 6.2.7.2, 7.5.4Effects of chemicals . . . . . . . . . . . . . . . . . . . . . . . 2.1Facepiece restriction . . . . . . . . . . . . . . . . . . . . . . 6.3.5Field of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.4.4Spectacles, use of . . . . . . . . . . . . . . . . . . . . . 6.2.7.2

WarningsAdequacy of . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.2.8By irritant action . . . . . . . . . . . . . . . . . . . . . . 6.2.8.2By odour . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.2.8.1

WearersseeScreening of usersWelding

Fume . . . . . . . . . . . . . . . . . . . . . . . . Figure 2.2, 2.2.3Protection factor . . . . . . . . . . . . . . . . . . . . . . . 6.2.2.2Respirator selection . . . . . . . . . . . . . . . . 6.2, Table 6.2

Work setsseeSCBA

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