RCF / ASW (aluminosilicate wools) - LADEPladep.es/ficheros/documentos/ecfia(1).pdf · RCF / ASW (aluminosilicate wools) ... Oxides such as zirconia, ferric oxide, magnesium oxide,

ECFIA – Representing the European High Temperature Wool Industry

RCF / ASW

(aluminosilicate wools)

Unifrax Health & Safety 2008 NEW 12/10/09 15:28 Page 1


CONTENTS

PREFACE

BACKGROUND (Recognition)

1 What is HTIW?

2 ASW/RCFproducts, uses and applications

3 How to recognise ASW/RCF products

4 Workforce and tasks

5 ASW/RCF is not asbestos

ASSESSMENT OF EXPOSURES (Evaluation)

6 The European CARE programme

7 Workplace concentrations associated with production and use of

ASW/RCF

8 Principal sources of dust

CONTROL OF EXPOSURES (Control)

9 General guidelines

10 Specific guidelines for the reprocessing of products

(secondary production)

11 Specific guidelines for end use in furnaces (installation and removal)

12 Specific guidelines for other end uses

CONCLUSION APPENDICES

A Expanded list of functional categories with definitions and examples

B Operations monitored in the primary production group

C Operations monitored in the secondary production group

D Operations monitored in the furnace-related group

E Operations monitored in the other end-uses group

F Generic trade names of RCF products from Unifrax

G ECFIA generic Material Safety Data Sheet (MSDS) for RCF products

H Respirable Crystalline Silica (RCS) in after use HTIW

Recognition and Control of Exposure to Refractory Ceramic Fibres (RCF)



page 3

PREFACE

HTIW (High Temperature Insulation Wools) are man made mineral fibres usedpredominantly in industrial applications. They have a unique combination oflight weight, low thermal conductivity, low volumetric heat capacity (low heatstorage), resistance to thermal shock, and ease of installation, to provideenergy efficient, high-temperature insulation (up to 1800°C).

The earliest and most important of these wools are Alumino-silicate wools also called Refractory Ceramic Fibres (ASW/RCF), which have been in use for over 50 years. Based on some several animal experiments RCF/ASW wereclassified by the EU as a category 2 carcinogen (Directive 67/548EEC) andshould be treated as if they were a human carcinogen. This classificationimposes a number of obligations on producers and users of ASW/RCFincluding the development of alternatives and substitution where possible.Many applications now use Alkaline Earth Silicate (AES) wools fortemperatures up to 1250°C.

It is also mandatory to reduce exposures to category 2 carcinogens to thelowest levels practicable thus minimizing any possible health risks. Since itsinception in 1979, the ECFIA representing the HTIW Industry in Europe hasactively promoted the safe use of ASW/RCF products through its productstewardship programme. One important aspect of the product stewardshipprogramme is the CARE (Control and Reduce Exposure) programme whichhas been running in Europe since 1996. The objective of this programme is to provide customers with professional and carefully tailored industrial hygieneadvice on reducing exposures to all ECFIA members’ products. As a result of the CARE Programme, ECFIA has amassed an impressive amount ofinformation and insight on exposures and control methods across a widecross-section of industries. Our intent in producing this guide is to share thisinformation and our experience in assessing and controlling exposures toASW/RCF. The document contains three sections:

Recognition: describes ASW/RCF and the products made from them, the workforce exposed, the tasks where ASW/RCF are used and highlightsfundamental differences between ASW/RCF and asbestos.

Evaluation: briefly presents the CARE Programme, shows dust concentrationsfor several industry sectors and reviews the principal mechanisms governingdust release and dust concentrations.

Control: provides an in-depth review of sources and control methods for these Industry groups. The emphasis throughout the guide is on providing the reader, whether a health and safety officer, company manager or otherprofessional seeking advice on ASW/RCF, with practical guidance onexposures and their control.




BACKGROUND

1. What are High Temperature Insulation Wools(HTIW)?

2. ASW/RCF products, uses and applications

3. How to Identify ASW/RCF products

4. Workforce and tasks

5. ASW/RCF is not asbestos

page 5




1 What are High TemperatureInsulation Wools (HTIW)?

The term HTIW describes a family of man made synthetic vitreous fibres thathave a range of compositions and uses.

The Chemical Abstract Service (CAS) defined ASW/RCFs under the name“Refractories, fibres, aluminosilicate”. (number 142844-00-6) as:-

“Amorphous man-made fibres produced from melting, blowing or spinning ofcalcined kaolin clay or a combination of alumina (Al2O3) and silica (SiO2).Oxides such as zirconia, ferric oxide, magnesium oxide, calcium oxide andalkali may also be added. Approximate percentages by weight of compoundsfollow: - Alumina: 20-80% - Silica: 20-80% - Other oxides in lesser amount”

European ASW/RCFs are high purity alumino-silicates containing 46-58% silicaand 42-54% alumina. The production also includes zirconia ASW/RCFscontaining 14-18% zirconia and 28-36% alumina with a silica content similarto that in the high purity fibres.

The AES Wools are included in CAS numbers 329211-92-9, 308084-09-5 and436083-99-7 and were developed by reformulating glass wool compositionsto increase application temperatures.

A third type of material is also a member of HTIW. These are polycrystallinealumina or mullite fibres produced by the Solgel process. These are particularlyuseful for very high temperatures where capital equipment costs are not crucial.

The term “ceramic fibre” has been used to describe many materials with verydifferent physical properties and chemical compositions, including: crystals orwhiskers of silicon nitride, silicon carbide or potassium titanate fibres. Thesecrystalline fibres are not HTIW and are not the subject of this guide.

AW/RCFs and AES wools are manufactured by random spinning or blowingprocesses and contain fibres with diameters and lengths that vary both withinindividual products and between different product types. The polycrystallinewools are made by a variety of processes all of which result in a narrowerdistribution of diameters.

page 7

Continuous filaments

Mineral wools

Refractory Ceramic fibresRCF

Alkaline Earth Silicate fibresAES

Microfibres

Vitreous (amorphous) fibres

One crystal fibres(Whiskers)

Polycrystalline fibres

Crystalline fibres

Mineral synthetic fibres Organic synthetic fibres

Man-made fibres


Their maximum use temperatures are far higher than those for asbestos, rock and glass fibres (Fig.1).

Experimental ASW/RCFs were first produced in the early 1940s andcommercial production began in the 1950s. The energy crisis of the 1970sand early 1980s encouraged their use because they were recognised as acost effective and energy efficient substitute for denser brick and castablerefractories. Their use as high-temperature insulation can reduce energyconsumption by more than 50% compared with alternative products. Table 1.1 shows the properties of ASW/RCF.

Table 1.1:

Fig.1:

Temperature ranges for

the use of inorganic

synthetic wools

page 8

• Maximum use temperature up to1800°C

• Low thermal conductivity

• Very low thermal mass

• Excellent resistance to thermal shock

• Low density

• Resiliency and flexibility

Polycrystalline wool (PCW)

Aluminiumsilicate wool

(ASW)

AES wool

Mineralwool


the RCF market:

a small proportion of

the artificial mineral

vitreous silica market

Percentage share of

RCF production for the

year 2005 in Europe

(Source ECFIA)

page 9

Continuous filaments18%

RCF 0,9%AES-Wool1,1%

Polycristalline Wool0,04%

Mineralwool 80%

The AES wools were developed during the 1980s and 1990s as therequirement was for more soluble and hence less biopersistent materials.Industry was concerned about health implications when using ASW/RCF andmoved on to looking for alternative insulation materials.

The world production of synthetic vitreous fibres (glass, rock, slag) is around 8million tonnes per year. ASW/RCF represents 2%, i.e. 160,000 tonnes. In 2005annual production of ASW/RCF in Europe was 25,000 tonnes, AES 17,750tonnes and PCW 2,500 tonnes.


ASW/RCF production processes consist of either blowing an air stream on themolten material flowing from an orifice at the bottom of the melting furnace(blowing process) or by directing the molten material onto a series of spinningwheels (spinning process).

The fibrous mass produced, known as “bulk fibre”, can be further processed intoblanket, which is needled to improve handling strength. Bulk fibre can also beconverted into many different product forms. Using processes similar to those inthe paper industry, bulk can be processed into boards, shapes, felts and papers. It can also be used for manufacturing textile products and mixed into cements andmastics. Blankets are often used directly, (e.g. as a furnace insulation material), butare also converted into blocks known as “Modules” (also used for furnacelinings),gaskets and other products. These conversion activities are undertaken bythe three ASW/RCF producers in Europe but also by more numerous independentcompanies (convertors). ASW/RCF products are shown in Photo 2.1.

ASW/RCF are energy efficient, high-temperature insulation for products usedthroughout industry, (e.g. steel, ceramics, petrochemicals, foundry, non-ferrousmetals, power generation, glass, chemicals, fertilizers, heat treatment, cementsand forging industries). Table 2.2 presents the major applications in theseindustries. The largest single use of ASW/RCF is for furnace linings and relatedapplications; accounting for approximately 65% of consumption. ASW/RCF havedisplaced conventional insulating refractories, such as castables and fire bricks,because of their superior physical and chemical properties and lower life-cyclecost. The use of fibrous insulation can save up to 50% of energy consumption in industrial furnaces and kilns compared with some conventional refractories.This results in a substantial reduction of greenhouse gas emissions (CO2),estimated at 100 million tonnes per annum in Europe, with the resulting benefit for the environment.

2 ASW/RCF products, uses andapplications

Photo 2.1:

HTIW Products forms

page 10


ASW/RCF are also used for other applications including those in the automotiveindustry, (e.g. catalytic convertors, metal reinforcement, heat shields, and airbags), aerospace, (e.g. heat shields), defence industries, fire protection andgeneral industrial insulation. The manufacture and uses of ASW/RCF can bedivided into four segments: primary production, secondary production, furnace-related and other uses. Recommendations provided within this guide are basedon industrial hygiene studies carried out in each of these sectors.

Table 2.2

Example of applicationsfor ASW/RCF

Applications Steel Ceramics Petrochem Foundry Non- Power Automotive Glass Otherferrous generation

Furnace linings ✓ ✓ ✓ ✓ ✓ ✓

Back up insulation ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓

Ingot mould linings ✓ ✓ ✓

Ladle covers ✓ ✓ ✓

Molten metal transp. ✓ ✓& distribution

Expansion joints & seals ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓

Burner quarls ✓ ✓ ✓ ✓ ✓

Turbine insulation ✓

Heat curtains ✓ ✓ ✓ ✓

Weld stress relief ✓ ✓

Pipe insulation ✓

Fire protection ✓ ✓ ✓

High temp. filtration ✓

Catalytic convertors ✓

Slow cooling blankets ✓ ✓

Primary Production(Bulk and Blanket)

Secondary production(convertors)

Modules,shapes,boards,paper,textiles

Furnace related Other uses

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In accordance with the EU Classification and Labelling Directive andRegulations all ECFIA members provide hazard warning labels for theirASW/RCF products. Please refer to the ECFIA web site for further details atwww.ecfia.eu.

Material Safety Data Sheets (MSDS) designed in accordance with Directive91/155/EC are available by referring to ECFIA website. By contacting yoursupplier’s purchasing department, it should be possible to find information on specific products. In order to help recognise those containing ASW/RCF,Appendix F lists trade names and types of products manufactured by thethree companies involved in the primary production of ASW/RCF in Europe:Unifrax, Rath, Thermal Ceramics. Note that other trade names could be usedby convertors or distributors. Contact them directly for information.

Recognising ASW/RCF products in-situ may be difficult. Bulk fibre resemblescotton wool. White needled blankets may be recognised by their characteristictexture of the surface, (see Photo 3.1). Rigid boards and moulded parts areusually a beige colour. However, a variety of other fibres might resembleASW/RCF, but the packaging of other products is usually different. It istherefore recommended to always keep products in their original packagingwhere trade names and any health and safety labels are visible. When in doubtas to the identity of a fibre, a bulk sample of the in-situ material should becollected and analysed by an expert laboratory.

How to Identify ASW/RCF products3

In addition MSDSs are

supplied for all

ASW/RCF products.

page 12

Photo 3.1


ASW/RCF are principally industrial products and are therefore handled byprofessional users and not the general public. These users should have accessto relevant product safety information, (e.g. material safety data sheets), expertadvice, (e.g. industrial hygiene personnel), specialised training, and personalprotection equipment. ECFIA estimates that the total workforce exposed toASW/RCF in Europe in 2005 was approximately 16,800.

Tasks performed can be classified into nine major job categories: primaryproduction, mixing/forming, finishing, assembly, module assembly, installation,removal, auxiliary operations, others (NEC). Refer to appendix A for detaileddescription.

Workforce and tasks4

page 13


Unfortunately ASW/RCF is quite often confused incorrectly with asbestos,which can be misleading. In fact the two fibre types have many fundamentaldifferences, (see Table 5.1).

1µm 1µmChrysotile - TEM RCF (ASW) - SEM

ASW/RCF is not asbestos5

page 14

Asbestos

Natural mineral - mined and processed

Wide variety of industrial and consumerproducts including asbestos-cementpipe, roofing tile, floor tile, wall covering,millboard, textiles, automotive brakeshoes, cements, building and pipeinsulation.

Crystalline

Principally longitudinal - fibres break apartinto an increased number of thinnerdiameter fibres. This increases theirairborne persistence, degree of difficultyin detecting fibres with PCOM, and mayresult in fibres of increased toxicity(Assuncao and Corn, 1975).

Relatively fine - depending upon the typeof asbestos, median fibre diametersrange from approximately 0.02 µm to0.45 µm (HEIAR, 1991).

Attribute

Origin

Applications

Form of fibre

Fibre fracture mechanism

Fibre diameter

Workplace concentrations(diameters)

ASW/RCF

Synthetic, made from alumina and silica

ASW/RCF is not an asbestos substitute.ASW/RCF is an industrial product usedfor such applications as high-temperature furnace and kiln insulationat temperatures >800° C.

Amorphous (vitreous)

Transverse - fibres break into shorterfibres with same diameter ultimatelybecoming dust (TIMA, 1993).

A function of production method, butgenerally thicker than asbestos (TIMA,1993). Mean diameter of aerosolreported as 1-1.5 µm (medianapproximately the same) in authoritativestudy (Mast et al., 2000).


ASW/RCF and asbestos have different physical, chemical and industrialproperties. Asbestos is not a refractory fibre and is used in a wide range ofconstruction materials, such as asbestos cement.

• ASW/RCFs are synthetic and produced as a glass wool with variablediameter tapering fibres and glass shot, this is formed into blankets andseveral other product forms

• ASW/RCFs are a relatively homogeneous group of materials made fromapproximately equal weight proportions of alumina and silica meltedtogether and fiberised by blowing or spinning. Some types have higherconcentrations of silica and in some a low concentrations of other oxidespredominately zirconia is added. These changes affect some aspects ofhigh temperature behaviour but have no significant effects on surfacechemistry or other putative health related properties.

• ASW/RCFs are confined to industrial applications and are not found in theenvironment

Attribute

Workplace concentrations(diameters)

Durability / Biopersistence

Exposure

Animal carcinogen?

Human carcinogen?

IARC classification

Regulatory status

Asbestos

Typically higher than ASW/RCF becauseof low diameters (Assuncao and Corn,1975).

In-vitro durability and in-vivobiopersistence of amphibole materialsubstantially greater than that forASW/RCF.

At one time, very large. Now eliminatedin many countries, but still very large incountries where usage permitted.

Several inhalation studies indicate thatasbestos (particularly amphiboleasbestos) is an animal carcinogen (IARC, 2002).

Numerous epidemiological studiessupport carcinogenicity of asbestos -there is some controversy over thecarcinogenic potency of chrysotileasbestos (Hodgson and Darnton, 2000).

Group 1 - the agent is carcinogenic tohumans (IARC, 2002).

Banned in many countries. EPAattempted to ban asbestos in the U.S.Bills now before Congress to banasbestos.

ASW/RCF

Typically lower than asbestos becausefibre diameters are greater.

More durable than many other SVFs,but less durable than amphiboleasbestos (Maxim, et al., 1999).

Approximately 25,000 in Europe and thesame in the United States.

RCC studies indicate that high doses ofASW/RCF have resulted in lung cancerand mesothelioma in rats and hamsters.Accurate interpretation is not possiblebecause of particulate contamination(Mast et al., 2000; Brown et al., 2005).

University of Cincinnati epidemiologystudy has not shown interstitial fibrosis,incremental lung cancer, or anymesothelioma (Walker et al., 2002;LeMasters et al, 2003; Lockey et al.,2002).

Group 2B-the agent is possiblycarcinogenic to humans (IARC, 2002).

Not banned in any country.Occupational exposure limits (OELs) arepublished in several countries.

Table 5.1: Comparison ASW/RCF with Asbestos

ASW/RCFs

page 15


• ASW/RCFs inherent characteristics mean that it is only applied to high-temperature, thermal insulation applications. As such, ASW/RCF is a niche-market product.

• The toxicity of ASW/RCF is suspected on the basis of confusing andconflicting experimental studies. ASW/RCF has no demonstrated humantoxicity. As a matter of precaution, and in accordance with the recentclassification of ASW/RCF, exposures must be controlled and kept as lowas possible. Control strategies and methods developed for asbestos shouldnot be automatically transposed to ASW/RCF without accounting for thefundamental differences between the two fibre types and the two markets.This guide outlines a series of precautions tailored to the use of ASW/RCFproducts. These are based on the more general requirements for theprotection of workers from carcinogens at work.

• ASW/RCF products contain some fibres in the respirable range, but overallASW/RCF fibres are much coarser than asbestos fibres, with diametersdistributed around 3 microns. Consequently, ASW/RCF products havelower potential for dust release, (see Table 5.2). Airborne ASW/RCF fibrestend to settle rapidly and have a lower probability of penetrating into thealveolar region of the lung

• Asbestos is virtually ubiquitous in human lung samples with concentrationsof up to about 106 fibre per gram of dry lung in non-occupationally exposedpersons being not uncommon.

• The toxicity of asbestos is proven by many human and experimental studies

• An important property determining dust release and control is the sizedistribution of fibres. Asbestos fibres are very fine. For example, thediameter of chrysotile fibrils is about 0.03 µm.

• Because of this small diameter, asbestos products can generate fibrousdust that remains airborne for long periods and, if inhaled, has a very highprobability of penetrating deep into the lungs. Almost all airborne asbestosfibres are in the respirable range (fibres with a diameter less than 3microns).. Length and diameter analysis by electron microscopy shows that the distributions of ASW/RCF and chrysotile airborne fibres are quitedistinct, with very little overlap. Phase-contrast optical microscopy candetect the vast majority of ASW/RCF airborne fibres, whereas transmissionelectron microscopy is needed for asbestos. For ASW/RCF dust, an opticalmicroscopy count will detect almost all fibres present; However, it mayreport only a few percent for asbestos.

Consideration of fibre size distribution is relevant for exposure controlstrategies. Owing to the low capacity for ASW/RCF dust to disperse into the general environment, it is more advantageous to concentrate efforts andresources on controlling the environment close to the worker. This can beachieved by a variety of measures; the best being complete or partialenclosure with dust extraction equipment. This should be properly adjusted to the aerodynamic behaviour of ASW/RCF dust.

ASBESTOS

page 16


ASSESSMENT OF EXPOSURES

6. The European CARE programme

7. Workplace concentrations associated withproduction and use of ASW/RCF

8. Principal sources of dust

page 17



6The European CARE programme

In 1996, ECFIA initiated an industrial hygiene assistance programme known as CARE:"Controlled and Reduced Exposure". (This programme does not yetinclude polycrystalline wools (PCW), however the care programme will start toinclude PCWs from the end of 2008.) The cornerstone of the programmeconsists of industrial hygiene surveys during which ECFIA hygienists evaluateworkplace control methods and monitor personal concentrations of fibrous dust.Workplace monitoring is carried out using the WHO-EURO method (Germanmethod ZH1/120.31). Personal samplers are used to measure concentrations in the workers' breathing zone. Fibre counting is done by an independantlaboratory using phase-contrast optical microscopy (PCOM) in accordance with WHO Euro counting rules. Average concentrations are recorded for themonitoring period (from 50 to 500 min.) and reported as Actual Time-WeightedAverages (ATWA). During the last nine years of the CARE programme, a total ofover 4,822 ATWA measurements were made. These measurements were theresult of regular monitoring at ECFIA primary production plants and of surveys at customers' premises. The customers included volunteers and customersselected at random with selection probability proportional to ASW/RCFpurchases in the preceding year. At the start of the programme customers were selected based on ASW/RCF products purchased.

Measurement from the ECFIA plants were taken on randomly selected workers.The secondary and end-user facilities were a mix of randomly chosencustomers and customers who had volunteered for the measurements.Analysis of concentrations showed no statistically significant difference betweenthose selected and those that volunteered. Workers were chosen within eachfacility to have a cross section of workers handling ASW/RCF. Samplingdurations at the secondary and end-users sites were sometimes less than thefull work shift. These ATWAs may overestimate the full-shift, time-weightedaverages. Further, the concentrations presented are those found in the workers'breathing zones. They do not account for respirator use, which correlated fairlywell with dust concentration. The workers actual exposures will have beenlower. The concentrations given here result from a mix of workplace conditions:from well-controlled to poorly controlled. Variations will occur from site to siteaccording to the process and control measures employed.

page 18


100

90

80

70

60

50

40

30

20

10

100

90

80

70

60

50

40

30

20

10

100

90

80

70

60 50 40

30

20

10

90

80

70

60

50 40

30

20

10

0

90

80

70

60

50

40

30

20

10

100

90

80

70

60

50 40

30 20

10

0

100

90

80 70 60 50 40

30

20

10

0

100

90

80

70

60

50

40

30

20

0

90

80

70

60

50

40

30

20

10

0.01

0.1

1

10

0.01

0.1

1

10

Functional Job CategoryData set: Fi rst - ninth-year CARE data (4,832 observations)

Assembly Auxi l iary InstallationFinishing MixingForming

Other RemovalFibreProduction

Modules

7Workplace concentrations associated with production and use of ASW/RCF

Figure 7.1 shows that priority must be given to secondary manufacture ofproducts (module assembly and finishing) and furnace-related applications(Installation and removals).

Mean concentrations were higher in “secondary production” and “furnace-related uses”. The ATWA values reported correspond to concentrationsaveraged over the monitoring period. Times profiles were not established.Instantaneous concentrations can obviously be higher or lower than the mean.

The ladder diagram shown in Figure 7.2 presents an example of thedistributions of ATWAs in selective group.

Fig. 7.1:

Mean fibre concentrations

across FJC

Fig. 7.2:

Ladder diagram:

Gives the percentage of

workplaces measured

below a given

concentration

page 19


In Europe, exposure limits for ASW/RCF are in the range of 0.10 f/ml to 1.0f/ml. Such limits can be used as reference points, even if strictly speaking anATWA figure cannot be compared to an 8-hour averaged exposure limit. Inmany operations, the use of HTIW during the work shift is far less than the full8 hours.

The objective is to reduce exposures to levels as low as technically possible.Industrial hygiene aims at reducing concentrations at the source.

The rest of the document emphasizes measures to reduce concentrations in these areas. Operations were classified in the eight job categories, (see Fig. 7.3). Concentrations (geometric means) associated with each category are reported in the bar chart. It can be seen that module assembly, finishingand removal operations carry the highest potential for exposure.

Geometric Mean (f/ml)

0.0 0.2 0.4 0.6 0.8 1.0

Removal

Finishing

Modules

Installation

Mixing/Forming

Assembly

Auxi liary

Other (NEC)

Fibre Production Nine Years' Data, Manufacturers and

Customers

Functional Job CategoryFig. 7.3:

Geometric Mean Fibre

Concentration by Functional

Category, Manufacturers

and Customers,

Nine Years' Data

page 20


8Principal sources of dust

All ASW/RCF materials can release dust: the amount depends on how the material is handled. High concentrations are usually found during removal of after-use ASW/RCF from furnaces and also during mechanical finishingactivities and in the assembly of modules. Where fibre products aremechanically abraded by sawing, sanding, routing or other machining theairborne fibre concentrations will be high if uncontrolled. Dust release is furthermodified by the intensity of energy applied to the product, the surface area to which the energy is applied, and the type, quantity and dimensions ofmaterials being handled or processed. Dispersion or dilution of dust produceddepends on the extent of confinement of the sources and the work area, as well as the presence and effectiveness of exhaust ventilation. Individualexposures depend on work methods, work organisation and the use andeffectiveness of protective equipment. The extent to which these materials are handled will also determine dust release and substantial effort should bedirected towards reducing it. In many cases, reorganization of work flow caneliminate handling steps and reduce exposures. Ideally, automation of part orall of a process should be considered, and will often yield gains in productivity.Airborne fibres generated by ASW/RCF materials are coarse and settle rapidly.As a consequence, ambient concentrations are often low (e.g., much less than0.1 f/ml). It is not unusual to find ambient measurements lower than personalmeasurements by a factor of ten.

page 21



CONTROL OF EXPOSURES

9. General guidelines

10. Specific guidelines for the reprocessing ofASW/RCF products (secondary production)

11. Specific guidelines for end use in furnaces

12. Specific guidelines for other end-uses

page 23



9General guidelines

ASW/RCFs are high temperature insulation products that should be used inapplications which require its unique combination of properties. These productsshould be limited to professional use only. Exposure to dust should bemaintained at low levels by correctly applying appropriate control measures.

Controls should always be applied in the following hierarchy:

• control or elimination at the source (e.g. using dust suppressed or pre-sized products);

• control between source and worker, (e.g. exclusion barriers, enclosure andexhaust ventilation

• control at the level of the worker, (e.g. information showing use of respiratoryprotective equipment).

Respiratory protective equipment (RPE) should be used only as a temporarycontrol measure, i.e. for short-term exposures that are otherwise difficult tocontrol and where concentrations are unknown. RPE should not be used as a long-term solution.

ASW/RCF products, in some cases, can be made virtually dust free by pre-cut, pre-shaped, encapsulated or coated with dust suppressants, to significantly reduce potential dust release. Use of dust-suppressed products should be encouraged.

Alternatively, wetting products with a fine clean mist of water prior to andduring handling can substantially reduce dust. If dust emissions cannot becompletely avoided or suppressed at their source, exposures should bereduced to the lowest achievable levels.

Enclose sources as much as possible to prevent unnecessary exposure.Segregation can be achieved by physical or airflow barriers.

Many instances of passive exposure are unnecessary and can be avoided by reorganizing the work area or work activities. All effort should be applied to avoiding unnecessary exposures. Work practices can usually be improvedto reduce the number of handling steps or their duration. Processes can beautomated to achieve the same end; this will often increase productivity.Automated stages of a process can be easier to enclose and extract the dustgenerated during the processing, e.g. Local Exhaust Ventilation (LEV) equipment.

Extraction systems must be designed to capture dust as close as possible to the sources. Design of the extraction hood to effect capture at source willminimize dust dispersion and reduce the volumes of air required. Extracted air

page 24


should undergo high-efficiency filtration and be treated according to localregulations. The air velocities required to control dust depends on the rate atwhich the dust is released from the product. As a general guideline, Table 9.1provides ranges of air velocities required to capture respirable ASW/RCF dust.For many manual handling operations, a well designed local exhaust ventilation(LEV) System will capture velocities between 0.5 and 1.0 m/s at dustgeneration points should ensure good control.

Photo 9.3:

Local exhaust extraction system for

assembly of RCF materials

Photo 9.4:

Mobile down-draught bench

Photo 9.1:

Down-draught table with integrated bin

for waste

Photo 9.2:

Down-draught system

Table 9.1:

Capture velocity value

depends on particle

velocity

Capture velocity required

at the point of dust

generation

0.5 to 1.0 m/s

1.0 to 5.0 m/s

5.0 to 25m/s

page 25

Example

Conveyor transfer, unrollingblanket, cutting blanketmost manual handling

Textile, spinning, weaving

Band sawing, machiningfinishing

Nature of source

Low velocity

Moderate velocityemissions

High velocity emissions


To ensure efficient control of dust sources and avoid errors, the design of the dust-control system should be carried out by an experienced ventilationengineer. Prior to implementation, the plans should be reviewed by theprocess operator and by an industrial hygienist.

After redesigning a workstation or implementing control measures, operatorsshould be trained in proper operating and handling procedures that will helpminimize dust, as outlined in the ECFIA “Code of Practice”. Waste and debriscan present a secondary source of exposure and should be controlled bygood housekeeping techniques. Dry sweeping and compressed air cleaningshould be prohibited. The work area and work surfaces should be regularlycleaned using a vacuum cleaner equipped with a high-efficiency filter.

Every employee who handles ASW/RCF should be familiar with the potentialhealth risks and with proper working procedures. Level P3 respiratoryprotection is recommended where excursions above the exposure limit areless than a factor of ten. Level P2 protection can be provided on a voluntarybasis for concentrations below the occupational exposure limit.

To prevent skin irritation (itching) and the contamination of employees' clothing,the use of disposable protective coveralls made from a material impervious tofibres is recommended.

The recommended control measures presented in this document take intoaccount the general principles imposed by European legislation and includepractices currently in use in certain industries. We have also indicated wherepossible the lowest levels documented during the CARE measurement programfor specific operations. For further information or assistance in controllingexposures to ASW/RCF dust, contact an ECFIA industrial hygienist.

page 26


10Specific guidelines for thereprocessing of ASW/RCF products(secondary production)

In secondary production, ASW/RCF in the form of bulk or blankets istransformed or processed to make product forms, such as vacuum-formedshapes, boards, felts and papers, cements, modules, die-cut parts andtextiles. As a general guide, Table 10.1 presents an overview of the main jobsand their associated concentrations.

To further guide the reader, the data are classified into four categories ofaverage concentration. Variations in work organization and tasks will result indifferent concentrations. Thus, information in Table 10.1 should serve only asgeneral indication of what to expect. The most important sources of dust arethe finishing (machining) operations in which fibrous products are subjected toconcentrated mechanical energy from powered equipment or machinery suchas sanders, saws, die-cutting presses, routers and others. The next mostimportant source is handling of fibre and fibre-based products. As can beseen in the Table, jobs in which these activities feature prominently tend tohave average concentrations in excess of 0.5 f/ml. Several activities will beexamined in further detail. They are: - vacuum forming - production ofmodules - production of die cut parts - machining. For each of these, a tableproviding a summary of emission sources, average dust concentrations andrecommended control methods is given.

Table 10.1:

Secondary Production,

main jobs and

dust concentrations

Jobs with arithmetic mean concentrations less than 0.2 f/ml

Means

Geom. Arith. Min Max N

0.088

0.110

0.123

0.127

0.147

0.175

0.022

0.010

0.024

0.640

0.378

0.760

14

28

24

Slitting and rolling of ASW/RCF

paper

Warehouse workers handling

wrapped/packaged ASW/RCF,

forklift drivers in the warehouse

Supervision of secondary

production tasks

Dry end paper

Warehouse/

forklift

Supervisor

page 27


Jobs with arithmetic mean concentrations between 0.2 and 0.5 f/ml

Means


0.160

0.139

0.231

0.187

0.157

0.134

0.214

0.214

0.233

0.314

0.279

0.222

0.231

0.263

0.266

0.277

0.288

0.292

0.310

0.390

0.408

0.436

0.020

0.010

0.040

0.010

0.010

0.020

0.010

0.010

0.020

0.161

0.015

0.960

1.016

0.633

1.345

1.823

1.393

1.140

1.468

3.127

1.404

1.208

39

56

24

231

44

20

76

58

182

9

47

QA/QC activities associated

with manufactured ASW/RCF

products

Other workers with passive

exposures (e.g., welders,

electricians, administrative

workers, production area forklift

drivers), and unspecified

auxiliary workers

Cutting ASW/RCF materials

with high-pressure water jet

Vacuum forming board,

shapes, and paper

Insertion, attachment,

application of ASW/RCF

materials to a commercial

product

Insertion, attachment,

application of ASW/RCF

materials to a commercial

product, with some finishing

Handling or packaging

ASW/RCF products

Making ASW/RCF textile

products such as rope or cloth

(e.g., operate loom, spinner,

carding machine)

Both wet mixing and forming

performed on a shift

Maintaining or cleaning of

secondary production area or

equipment

Laminating or encapsulating

ASW/RCF (e.g. with aluminum

foil)

Quality control

Auxiliary

Water jet cutting

Vacuum forming

Assembly with

ASW/RCF

Assembly with

ASW/RCF,

some finishing

Packaging

Textile

manufacture

Mixing and

forming

Maintenance /

Cleaning

Laminating /

Encapsulating

page 28



Means


0.325

0.503

0.353

0.596

0.489

0.503

0.453

0.546

0.604

0.584

0.779

0.474

0.521

0.651

0.661

0.697

0.702

0.769

0.771

0.784

0.830

0.849

0.943

0.972

0.019

0.100

0.054

0.199

0.026

0.05

0.05

0.080

0.116

0.041

0.220

0.015

4.028

2.341

3.190

1.820

4.638

3.597

4.084

3.509

4.038

3.244

3.219

16.020

150

66

18

36

189

177

119

31

38

61

22

67

Wet mixing ASW/RCF for

vacuum forming boards,

shapes or paper

Handling or packaging

ASW/RCF products in close

proximity to to a finishing

operation

Dry mixing fo bulk ASW/RCF

with other ingredients (for

vacuum forming or cements)

Operate board sander

All jobs connected with

production of ASW/RCF

modules (folding, trimming,

attach hardware, etc.)

Operate die cutting machine

and take-off of product

Cut various materials on a

power saw (circular saw, table

saw)

Operate board saw

Power sanding of formed

ASW/RCF product

Finishing using hand tools

Operate both of these

machines

More than one finishing task

during the shift

Mixing

Packaging in

finishing area

Dry mixing

Board sanding

Module

production

Die cutting

Cutting, sawing

Board sawing

Sanding

Hand finishing

Board Sanding

& Board Sawing

Multiple finishing

tasks/

miscellaneous


Means


0.824

0.798

1.777

3.822

1.212

1.360

2.358

3.822

0.123

0.1

0.188

3.822

6.060

5.600

5.708

3.822

58

58

16

1

Operate these power tools

(hand held or fixed installations)

Cut various materials on band

saws

Operate linisher

Operate ball mill to mill bulk

ASW/RCF

Drilling, grinding,

routing, lathe,

milling

Band sawing

Linishing

Ball milling

page 29


Vacuum-formed (VF) products are shapes produced from bulk fibre in a five-stage process, with operators involved at each stage: mixing, forming,drying, inspection and packaging (Table 10.2). At the mixing stage, theoperator introduces dry ingredients in to the mixing tank (typically starch andbulk ASW/RCF). Additional wet ingredients are added last (typically colloidalsilica). The forming stage is the "wet-end" of the process, where VF shapesare formed using a mould and suction, the shapes are removed and placed on a drying rack in a curing oven. At the packaging stage, dried VF shapes aremanually removed from the drying rack, inspected and packed into boxes.

Exposures are concentrated in the dry ends of the process when adding dryingredients to the mix and when handling the dried shapes (unloading, packingand inspection).Compression of empty bags into waste can also release dust.

1 Complete or partial cover on the mix tank. 2 Delivery chute at HTIW introduction point. 3 Spillage of materials around tank should be immediately cleaned.4 Water spray applied at the point where dry materials are added. 5 LEV hood at dry ingredients weigh station.6 LEV hood at HTIW introduction point.7 Wetting of used bags prior to disposal.8 Segregate wet process from the dry operations such as packing and

inspection.9 Use appropriate personal protective equipment (PPE) including respiratory

equipment.

Secondary exposure can occur where there is re-suspension of spilt materials,this can be addressed with good housekeeping. Vacuum cleaners fitted withHEPA filter should be used to clean up dry spillages. A wet scrubbingtechnique should be used where practical at the end of each shift.

Control methods for

vacuum forming and

other wet mixing

processes

Controls

page 30

Photo 10.1

Forming station

Photo 10.2

Packaging of RCF boards


Table 10.2: Control methods for vacuum-forming

0.325

0.187

0.233

0.214

0.503

0.521

0.266

0.390

0.292

0.651

0.019

0.010

0.020

0.010

0.100

4.028

1.345

3.127

1.140

2.341

150

231

182

76

66

Slitting of bags

Manual loosening and pushing of

fibre into tank

Compression of empty fibre bag

into waste container

Spillage of fibre around tank

Negligble sources due to mainly

wet process

If concentrations are elevated,

likely cause are other dusty

process or dried out material

being disturbed

As above

Dried shapes are friable

Handling of the VF shapes during

removal from drying racks,

inspection and packaging

Hand removal or surplus edges

Note that packing boxes are often

reused and unless pre-cleaned

using a vacuum, will accumulate

dust and debris in the bottom of

the box

As above

Mixing

Vacuum forming

Mixing and

forming

Packaging

Package in

finishing area

MeansGeom. Arith. Min Max N

Job Sources of exposure

ranked by importance

Recommended controlmeasure

page 31

Use of soluble bags for bulk

fibre

- Automatic opening of bag and

feed in to tank

- complete or partial cover on

tank

Delivery chute at fibre

introduction point

Water spray where fibre is

introduced into tank

LEV hood at dry ingredients

weigh station

LEV hood at fibre introduction

point

Wetting of used bags prior to

disposal

Use vacuum with HEPA filter to

clean up dry spillage

PPE/RPE

Segregate the forming

operations from other dusty

processes (e.g fininshing)

Wear impervious gloves to

prevent irritation and drying of

skin

PPE/RPE

As above

Change work methods to

minimise extent of handling

and movement of pieces

around the work area

Use fine water mist on parts to

suppress dust prior to packing

Use new or pre-vacuumed

boxes for packing

Conduct inspection and

packing in a ventilated booth.

Maintain good housekeeping

at all times using a wet

scrubber and or vacuum

containing HEPA filter.

Use correct PPE and RPE

As above


Modules and veneers are laminated blocks of blanket, which are eithermanually produced or produced by a semi automatic process. (Table 10.3).

ASW/RCF blanket is hand cut into sections using a template and a hand knife. Sections are stacked onto a pallet. Waste fibre is bagged or boxed. At completion, the sections are transferred to an assembly area. For theassembly, the pre-cut sections are inserted into a magazine for compressionto the desired thickness. Compression is maintained by application of straps,tape, metal clasps, or by insertion of the module into a plastic bag. Modulesare often pierced to allow insertion of metal fixtures. Modules may be trimmedusing a band saw or circular saw, either at this stage or prior to compressing.Band sawing of blanket can produce very high concentrations of fibrous dust.Consequently, particular attention should be paid to this step of the process.

The semi-automatic process is typically used to produce standard sizedmodules. One variant of this process uses sections of blanket that have beenprecut on a die-cutting press (see die-cutting). Stacks of precut sections ofblanket are manually positioned into a press that automatically compresses the block. Straps, tape or extrusion into a plastic bag are used to maintaincompression. Metal fixtures are added automatically or manually. Modules arepacked into cartons or on pallets.

The pleated blanket process uses rolls of blanket directly. Rolls of fibre areunwrapped and loaded into a folding machine. The standard size blanket is fed manually or automatically. After a certain number of folds a cross-cutsaw is activated. Pleated sections are manually transferred to a press andcompressed to the desired size. Compression is maintained as in the manual or pre-cut process. Metal fixtures are added and modules are packedinto cartons.

Veneer modules are thin modules usually produced by hand. Precut strips of blanket are manually placed on edge into a compression jig. Strips areattached either by plastic mesh or by strips of glue along the cut edges of the blanket. Assembled modules are then trimmed and packed into cartons.

Modules and

Veneers

Manual production:

Semi Automatic

Production:

page 32


Table 10.3: Control methods for production of modules and veneer modules

0.489 0.702 0.026 4.638 189MANUAL PRODUCTIONSegregate the module/veneerassembly area. Restrict accessonly to operators involved in theprocess.Minimise manual handling byreorganising the work; reducedistances between operationsUse an extraction booth withdowndraft table (with integratedwaste bin) for unwrapping,unrolling, cutting and stacking ofparts. The table should be largeenough to allow all dustproducing operations to becarried out on its surface, withinthe dust capture zones providedby the exhaust system.The table should be designed toprovide at least 0.5 m/s ofcapture velocity at the pointswhere dust is generated.Use fine water mist on productprior to and during compressionand folding.Bag waste material immediately,label and store in segregatedarea.

BANDSAWReplace the band saw blade with a “band knife” or finetoothed saw without tooth offset.Segregate the band saw fromother operations.Ensure adequate LEV at the 3main dust generation points:– at the height adjustable bladeguide above the work table- directly below the table wherethe blade exits the blanket- immediately after the 6 o’clockposition of the lower drive wheelinside the guard housing.Between 600 and 800 m3/h ofexhaust air is normally requiredfor each dust collection point.

COMPRESSION PRESSESEnclose press as much aspossible, install LEV to capturedust from press, from insertionof block into plastic bag,insertion of metal fixtures, andfrom packing.

OTHERConduct QC tests on downdrafttable.Clean work equipment andsurfaces regularly during shiftusing a HEPA equipped vacuumcleaner.Use disposable clothingimpervious to fibres.Use RPE appropriate toexpectedconcentrations(typically P2 or P3)

Unwrapping, unrolling of blanketHand cutting of blanketHand folding of blanketHand stacking of blanketBagging of waste fibreCompressing stacks of blanketInserting into plastic bagAdding metal fixturesConducting QC testingPacking

Manualproduction ofmodules

Means


Job Sources of exposure

ranked by importance

Recommended control

measure

page 33


Die-cut parts are produced from flat sections or rolls of fibrous product(blanket, paper or felt) in a manual or semi-automated die-cutting press. Inmanual die-cutting, the operator unrolls blanket, paper or felt onto a table,cuts rectangular sections with a hand knife and stacks the rectangles on apallet as feedstock for the press. Several layers of ASW/RCF are then placedon the press table, advanced under the press and die cut (Photo 10.4).

The operator then withdraws the table from the press, removes the die cutpieces for packing, and removes the waste trims to a bag or box. In semi-automated die-cutting, rolls of blanket, paper or felt are loaded onto the feedsection of the press and unrolled. The product is fed through the press, asection is die-cut, the product advanced and the die-cutting repeated. At thetakeoff end of the press, operators manually remove cut pieces and stack onto pallets or into boxes. Waste edge trims are also manually removed andcompressed into bales. The most important sources of dust are the die-cuttingplate, handling of the die-cut pieces and handling of the waste trims.

Concentrations during loading and alignment of the rolls can be elevated, but are brief. Concentrations can be substantially reduced by enclosing thepress and providing proper dust extraction at the sources. More moderncutting techniques can dramatically reduce concentrations. For example, high-pressure water-jet cutting produces essentially no dust and leaves dampedges that further reduce dust during handling of cut pieces. In another newprocess, blanket is unrolled onto a suction table, then covered by a plastic filmand maintained in place by suction applied beneath the blanket (photo 10.3).

A small, computerized knife-cutting head cuts pieces to the desired shape,with very little dust emission. During handling of the cut parts, however, dustconcentrations of about 0.5 to 1.0 f/ml are typical unless handling is doneunder local exhaust ventilation.

Die Cutting of

fibre products

page 34

Photo 10.3 (Automatic)

Blanket held under plastic film

on suction table.

Photo 10.4 (Manual)

No exhaust ventilation or other controls.


Table 10.4: Control methods for production of die-cut parts

0.503 0.769 0.002 3.597 177Segregate the die-cutting area.

Restrict access to the press -

Unwrapping, unrolling of

blanket only to be operators

involved in process

Hand picking of cut pieces -

Ensure adequate LEV around

all sides of die cutting

equipment

- Hand stacking of pieces on

pallets cutting tools - Packing

into boxes - Enclose press as

much as possible - Handling,

compression and bagging of

fibre pieces

- Enclose take-off area and

extractdust, design so that

airflow is downward (e.g. Slot

hoods level with take off table)

Install automated waste trim

take off with LEV

Ensure LEV at pallet packing

and box packing stations use

adjustable table to allow

packing at correct height

Conduct QC tests on down

draught table

Clean work equipment and

area regularly during shift using

a HEPA vacuum cleaner

Use disposable clothing

impervious to fibres.

Use RPE appropriate to

expected concentrations

(typically P3)

- Die cutting plate, jig

- Unwrapping, unrolling of blanket

- Hand picking of cut pieces

- Hand stacking of pieces

on pallet

- Packing into boxes

- Handling, compression and

bagging of waste fibre

- Conducting QC testing

Die-cutting

press operator


Job Sources of exposureranked by importance


LEV – Local exhaust ventilationPPE- Personal protective equipmentHEPA – High efficiency particulate arrester.

page 35


Table 10.5: Control methods for machining

0.596

0.546

0.604

0.798

0.453

0.824

0.697

0.784

0.830

1.360

0.771

1.212

0.199

0.080

0.116

0.033

0.008

0.123

1.820

3.509

4.038

5.600

4.084

6.060

36

31

38

68

119

58

Segregate the machining area,

restrict access only to

operators involved in the

process.


sources of emissions, at points

where machining head or tool

is in contact with HTIW.

Ensure adequate LEV at

machine entry and exit.


manual handling and stacking

(packing) operations.

Enclose machines as much as

possible and extract dust

close to the dust generation

points.

Clean work equipment and

surfaces regularly during shift

using HEPA –equipped

vacuum cleaner.

Use disposal clothing

impervious to fibres

Use RPE appropriate to

expected concentration

(typically P2 or P3 filters)

Application of concentrated

mechanical energy to abrade,

cut or machine HTIW product

Handling, packing and

stacking machined HTIW

product into boxes or onto

pallets

Handling of HTIW prior to

machining

Removal of packaging from

HTIW product

Sanding,

Sawing,

Routing,

Milling

Board

sanding

Board

sawing

Sanding

Band

sawing

Cutting,

sawing

Drilling,

grinding,

routering,

milling


Job Sources of exposureranked by importance


page 36

Photo 10.5

Belt Sander equipped with local

exhaust ventilation, air-jet stripper,

enclosure of entry and exit points,

and waste capture bins.

Photo 10.6

Local exhaust ventilation hood on horizontal band saw.


page 37

11 Specific guidelines for end use in furnaces

HTIW are commonly used as a high-temperature insulating lining insidefurnaces and kilns in the metallurgical, steel, petrochemical, chemical andceramic industries.

The life-cycle of ASW/RCF in furnaces has three stages: installation, use andmaintenance of the furnace, and removal. The installation and removal ofASW/RCF are dust producing jobs that require preventive measures. Once in place, ASW/RCF insulation will not produce dust during use of the furnaceunless there is abrasion of the lining. The service life of ASW/RCF insulation ina furnace is typically several years, depending on the application. Furnacedismantling and rebuilding operations can produce high concentrations of dustif certain preventative measures are not taken. Such operations include theremoval of furnace lining insulation at the end of its service life. There are fourreasons for the potentially high concentrations: 1/ after-use ASW/RCF materialis extremely friable - 2/ a large volume of material is removed - 3/ removaltakes place in a confined space, often with inadequate dust extraction - 4/ there is pressure to remove material quickly.

Photo 11.1

Refractory Industry:

RCF insulation inside a furnace.

Photo 11.2

Glass Industry: installation of RCF

blanket into expansion joint of a

new furnace.


This work should be carried out by trained teams of specialized contractorsequipped with air-supplied respirators and disposable clothing. Thedismantling and rebuilding of a furnace can result in exposures to otherhazardous materials such as crystalline silica, heavy metals and rock-woolfibres, depending on the application. Health hazards must be correctlyidentified and controlled, in addition to the preventive measures takenspecifically for ASW/RCF. Note that after extended periods above 900°C,ASW/RCF can partially convert to various phases of crystalline silica (refer toappendix H). This silica fomation is within the matrix of the fibre itself. Technical measures to prevent exposure to ASW/RCF and other dusts arebest anticipated at the planning stage. These measures should be designed to reduce dust emissions and limit personal exposures to the lowest levelpracticable. They should be listed in the project specification and integratedinto the prevention programme: clearly specifying organization andimplementation. As a general guide to the dust concentrations that can beexpected for furnace-related jobs, Table 11.1 presents an overview of the mainjobs and the associated dust concentrations. Actual concentrations in a givenapplication will vary according to the dimensions of the furnace, the nature andquantity of ASW/RCF insulation employed and the work methods andpreventive measures used. Overall, average dust concentrations for furnace-related applications were 1.7 f/ml. Dust concentrations for wet removal and5f/ml for dry removals were highest during dry removal of ASW/RCF (average5.03f/ml, average sampling duration 2 hours). Note that by properly wettingASW/RCF, after it has cooled down to typically 50°C, can reduceconcentrations, on average, by a factor of three (1.75 f/ml, average samplingduration 2 hours).

The installation of ASW/RCF materials generates lower average concentrations( 0.886 f/ml ). Dust concentrations for workers in the vicinity of a furnace whilstASW/RCF materials were being installed or removed were indirectly exposedto generally low dust concentrations (0.122 f/ml). This demonstrates thatASW/RCF fibres tend to settle rapidly

page 38

Removal

Photo 11.3

Steel Industry: wetting of

after-use RCF prior to removal.

Photo 11.4

Steel Industry: removal of after-use

RCF from a furnace.


page 39

0.38

7

0.68

3

0.74

9

0.83

1

0.08

1

Wet

rem

oval

Dry

rem

oval

0.88

6

0.84

4

1.75

1

5.03

4

0.12

2

0.01

5

0.18

0

0.08

0

0.05

0.05

6.16

6

2.16

6

5.45

6

53.6

16

0.39

2

84 30 9 52 21

270

309

110

176

321

Use

pre

cut,

pre-

size

d pi

eces

whe

re p

ossi

ble

If po

ssib

le, p

erfo

rm a

ll cu

ttin

g in

a s

egre

gate

d ar

ea, r

estr

ict

acce

ss o

nly

to o

pera

tors

invo

lved

in t

he p

roce

ssP

erfo

rm a

ll cu

ttin

g on

a d

own

drau

ght

tabl

e

Wet

sur

face

prio

r ta

mpi

ngC

lean

up

wor

k ar

ea r

egul

arly

dur

ing

the

shift

usi

ng a

HE

PAeq

uipp

ed v

acuu

m c

lean

erP

rohi

bit

use

of d

ry b

rush

ing

and

com

pres

sed

air

clea

ning

Bag

and

sea

l was

te im

med

iate

lyU

se d

ispo

sabl

e cl

othi

ng im

perv

ious

to

fibre

sU

se R

PE

app

ropr

iate

to

expe

cted

con

cent

ratio

n (ty

pica

lly P

2or

P3

filte

rs)

Enc

lose

and

seg

rega

te r

emov

al u

sing

pla

stic

she

etin

g or

poly

then

eIf

poss

ible

pre

wet

ting

of A

SW

/RC

F sh

ould

be

appl

ied

Use

wat

er la

nce

for

rem

oval

or

Use

vac

uum

-tru

ck fo

r re

mov

alP

rovi

de m

ultip

le v

acuu

m h

oses

(filt

ered

and

ven

ted

outs

ide

encl

osur

e)fo

r co

nven

ient

cle

anup

of s

pilla

ge o

r us

e po

rtab

leH

EPA

vac

uum

sE

nsur

e th

orou

gh p

enet

ratio

n of

wet

ting

agen

t th

roug

hout

AS

W/R

CF

laye

r (u

se d

ilute

det

erge

nt)

Bag

was

te a

s so

on a

s po

ssib

le a

nd d

ispo

se o

f AS

W/R

CF

into

cov

ered

con

tain

er /

skip

.C

lean

wor

k ar

ea r

egul

arly

dur

ing

shift

usi

ng H

EPA

vac

uum

sP

rohi

bit

use

of d

ry b

rush

ing

and

or c

ompr

esse

d ai

r cl

eani

ng.

Use

dis

posa

ble

clot

hing

impe

rvio

us t

o fib

res.

Use

indu

stria

l glo

ves

and

RP

E a

ppro

pria

te t

o th

e ex

pect

edco

ncen

trat

ions

(typ

ical

ly T

HP

3)R

estr

ict

area

to

wre

ckin

g or

inst

alla

tion

area

to

wor

kers

dire

ctly

invo

lved

in p

roce

ss

Han

d cu

ttin

g H

TIW

Han

dlin

g m

ater

ials

dur

ing

inst

alla

tion

Tam

ping

sur

face

s of

HTI

W m

ater

ials

Han

dlin

g w

aste

mat

eria

lsC

lean

up o

f wor

k ar

eaH

and

cutt

ing

HTI

WH

andl

ing

HTI

W m

ater

ials

dur

ing

inst

alla

tion

Tam

ping

sur

face

s of

HTI

W m

ater

ials

Han

dlin

g w

aste

mat

eria

lsC

lean

up o

f wor

k ar

ea

Bre

akin

g of

afte

r -

use

HTI

W m

ater

ials

Han

dlin

g of

afte

r -

use

HTI

W m

ater

ials

Scr

apin

g re

sidu

al H

TIW

from

furn

ace

surfa

ces

Cle

anup

of w

aste

fibr

e on

floo

rs a

ndsu

rface

s

Pre

senc

e in

wre

ckin

g or

inst

alla

tion

area

Inst

alla

tion

of H

TIW

Inst

alla

tion

of H

TIW

with

som

efin

ishi

ng o

rta

mpi

ng

Rem

oval

Aux

iliary

Mea

nsG

eom

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12 Specific guidelines for the use in furnaces

The versatility of ASW/RCFs means that they are employed in a wide variety ofindustrial applications. For convenience, applications in "Other end-uses" aregrouped by industry sector.

• Removal of ASW/RCF from kiln cars and moulds, Installation of ASW/RCF • Careful handling practices • Provide adequate PPE

• Removal of ASW/RCF blanket from casting moulds , Unrolling, cutting andinstallation of ASW/RCF blanket onto moulds

• Use automated water-lance system to remove ASW/RCF instead of dryabrasive blasting or manual removal

• Unroll, cut and install ASW/RCF blanket on down-draught tables

• Removal of ASW/RCF blanket from moulds, Unrolling, cutting andinstallation of ASW/RCFblanket onto moulds

• Carry out removal under local exhaust ventilation • Unroll, cut and install ASW/RCF blanket on down-draught/back-draught

table

• Die-cutting or sawing ASW/RCF (uncommon), Handling of ASW/RCF parts,Cleaning of work area

• Purchase pre-cut or preshaped pieces, preferably coated with dustsuppressant

• If cut on site, use cutting techniques that minimize dust and provideadequate extraction ventilation at dust generation points (especially bandsaws)

• Assemble ASW/RCF materials on down-draught tables (can achieve lessthan 0.1f/ml)

• Manual handling during assembly with ASW/RCF • Purchase pre-cut or pre-shaped pieces, preferably coated with dust

suppressant • Assemble RCF materials under LEV (can achieve <0.1 f/ml)

• Maintenance of kiln cars (remove after-service ASW/RCF, reline),load/unload bricks

• Careful handling practices • Provide adequate PPE

Abrasives

Aerospace

Aluminium

Boiler

Bricks

Automotive

(exhaust systems)

page 40


page 41

• Manual handling during assembly with RCF materials, Quality control testing • Use pre-cut or pre-shaped pieces, preferably coated with dust suppressant • Assemble ASW/RCF materials under LEV (can achieve less than 0.1 f/ml)

• Manual handling during assembly with RCF materials, Quality control testing• Use pre cut or pre shaped pieces, preferably coated with dust suppressant• Assemble RCF materials under LEV (can achieve <0.1 f/ml)

• Removal of after-use ASW/RCF from casting, Removal of RCF from kilncars, Cutting and installation of RCF material into moulds, Indirect exposureto foundry operators working in adjacent areas

• Prohibit compressed air cleaning of moulds, replace by brushingaccompanied by local exhaust ventilation

• Prohibit sweeping of kiln car, instead, use a vacuum cleaner with a HEPAfilter

• Provide local exhaust ventilation for cutting and installation operations • Provide adequate RPE for mould cleaning operations (e.g. THP 3) • Provide adequate RPE to indirectly exposed operators (e.g. FFP2)• Restrict access to work area to authorised and trained personnel.• Apply careful handling practices• Pre-wet used RCF prior to removal where possible• Bag and contain fibre waste immediately to prevent secondary exposure

• Wrap moulds with ASW/RCF, remove ASW/RCF from moulds, end-use ofmoulds in glass making

• Carry out removal under local exhaust ventilation (LEV)• Unroll, cut wrap RCF on down-draught or back draught table

• Maintenance of kiln cars (remove after-service ASW/RCF, reline),maintenance of furnace lining (install/remove), end use kiln cars andfurnace in ceramics manufacture



• Provide local exhaust ventilation for cutting and installation operations• Provide adequate RPE for mould cleaning operations (e.g. THP 3)• Provide adequate RPE to indirectly exposed operators (e.g. FFP2)• Restrict access to work area to authorised and trained personnel.• Apply careful handling practices• Pre-wet used RCF prior to removal where possible• Bag and contain fibre waste immediately to prevent secondary exposure

• Manual handling during assembly with RCF• Purchase pre cut or pre shaped pieces, preferably coated with dust

suppressant• Assemble RCF materials under LEV (can achieve less than 0.1f/ml)• Provide adequate RPE to indirectly exposed operators (e.g FFP2)

Domestic appliances

Fire protection

Foundry

Glass

Industrial Ceramics

Industrial Equipment


• Removal of RCF blanket from casting moulds, Removal of RCF from kilncars, Unrolling, cutting and installation of RCF, Indirect exposure ofoperators working in adjacent areas



• Provide local exhaust ventilation for cutting and installation operations• Provide adequate RPE for mould cleaning operations ( e.g. THP 3)• Provide adequate RPE to indirectly exposed operators (e.g. FFP2)• Restrict access to work area to authorised and trained personnel.• Apply careful handling practices• Pre-wet used RCF prior to removal where possible• Bag and contain fibre waste immediately to prevent secondary exposure

• Handling finished ASW/RCF products (generally wrapped and/orpalletized), move with forklifts, load trucks for shipping

• Careful handling practices should be applied

Overall, the concentrations are low ,the highest potential for exposure can befound during the removal of after-use ASW/RCF materials from kiln car, ladlesor moulds in foundries and the steel industry.

The average concentrations produced by these activities were 0.6 f/ml;substantially lower than those found during removal of ASW/RCF fromfurnaces. This is because "other end-use" removal work is usually carried outin open areas and involves small quantities of ASW/RCF. The most commonlyencountered operation is assembly work. Here, ASW/RCF materials areinserted into, attached to or applied to other materials to form an intermediateproduct or a finished, commercial product. When no finishing operations areinvolved, (e.g. cutting, trimming, sanding), average concentrations of dust forassembly operations were 0.25 f/ml (n=111). With finishing, concentrations ofdust were higher by a factor of four (0.82 f/ml, n=21). Dust concentrations forworkers indirectly exposed, (e.g. supervisors and fork lift drivers) were low, onaverage 0.18 f/ml (n=39).

The variety of applications covered in "other end-uses" prevents a thoroughexamination of concentrations by application. Instead, examples are providedto show how the CARE programme has improved the workplace. The firstexample given is a detailed procedure for working safely with ASW/RCF,developed by a major European steel producer. The second example showshow a car exhaust system manufacturer reduced already low dustconcentrations further, by careful attention to dust sources, information andtraining of workers.

Steel

Warehouse

Control methods for

other end uses

page 42


page 43

Photo 12.1

Installation of die-cut RCF blanket

into catalytic converter shell, on

downdraft table.

Photo 12.2

Installations of RCF blanket onto casting

mould, inside backdraft exhaust booth.

This procedure specifies the precautions required when working with materialscontaining ASW/RCF. Applications of these measures will provide adequateprotection of workers directly handling these materials and workers in thevicinity of these operations.

This procedure is applicable to all ASW/RCF materials, notably boards and textilesas used in high temperature insulation. The procedure applies to the construction,maintenance and dismantling of thermal installations containing ASW/RCF.

Where conditions allow, alternative thermal insulation products exempt fromany carcinogenic classification should be considered.

Authorisation to work with ASW/RCF is granted by the employers’s medicalofficer, who guarantees that the employee is:

• medically fit for work• informed of health risks• Trained in safe working procedures, including the proper use of Personal

Protective Equipment (PPE).

Dust levels associated with various operations involving ASW/RCF depend onhow the material is used. It is useful to distinguish four categories ofoperations that are likely to present different exposure potentials:

a) Assembly of high temperature insulation components b) Installation of assembled components, or episodic intervention on the

insulation, (e.g. maintenance)c) Removal of componentsd) Work conducted outdoors

Example 1:

Safe working

procedure for

ASW/RCF materials in

the steel industry


page 44

Assembly operations essentially consist of cutting ASW/RCF materials with a knife or a saw, then inserting or applying the ASW/RCF insulation to othercomponents. Such operations can produce substantial quantities of dust, butonly over short periods. Cutting with hand tools is preferred to using power tools.If power tools must be used, those with low rotational speeds are preferable

Cutting should be carried out on a downdraught table or, if not possible, inside an enclosure. The enclosure limits dust dispersion and clearly identifiesthe cutting area. Access to the enclosure should be formally restricted toauthorised operators equipped with appropriate PPE and RPE. Smoking,eating or drinking should not be allowed inside the enclosure.

The quantities of ASW/RCF unpacked on the work site should be limited tothe amount required for the job at hand. Prepared insulation should betransferred to the point of use in plastic bags or boxes. New materials shouldbe stocked in a manner that preserves packaging integrity. Unused materialsshould be repacked. The work site should be kept clear of all waste fibre.Waste ASW/RCF materials should be placed immediately into tear resistantplastic bags, sealed and labeled “Refractory Ceramic Fibre”. Floors and worksurfaces should be regularly cleaned during the work shift by vacuum cleaning(HEPA filtration) or wet cleaning. Dry sweeping and use of compressed airshould be prohibited.

The number of operators allowed on the work site must be limited. The operators must wear the following PPE: • Full-face respirator with powered filtration (level P3)• Disposable protective clothing impervious to fibres, closed at wrist and neck• Gloves to prevent skin irritation

After completion of cutting and assembling operations, the enclosure shouldbe vacuumed clean. Protective clothing should also be vacuumed clean, thenremoved and disposed of in a plastic bag.

A work zone is determined in which air-borne fibres can be generated. Thiszone is clearly marked-off by tape or rope, accompanied by signs and apictogram prohibiting access to persons not equipped with a type P3respiratory protective device.

Operators within the zone should wear:• Type P3 respirator• Gloves • Safety glasses• Disposable protective clothing impervious to fibres, closed at wrist and

neck and fire-retardant if necessary.

Whenever possible, the work zone should be maintained wetted or treatedwith a coating or rigidiser. Smoking, eating or drinking should not be allowedwithin the zone. A list of authorised personnel should be posted.

Installation of

assembled

components, or

episodic intervention

on the insulation,

(e.g. maintenance)

Assembly of

high temperature

insulation components


page 45

Removal of ASW/RCF insulation can generate substantial quantities of dustbecause aged insulation is brittle and extensive manual operations may berequired for complete removal, (e.g. brushing, scraping, grinding). If theremoval work zone cannot be enclosed or sealed off, the boundaries of thezone must be determined by experience or by measurements. The zoneshould be clearly marked-off by tape or rope, accompanied by signs and apictogram prohibiting access to persons not equipped with a type P3respiratory protective device.

Operators within the zone should wear:• Full-face respirator with powered filtration (level P3)• Disposable protective clothing impervious to fibres, closed at wrist and

neck and fire-retardant if necessary• Gloves to prevent skin irritation and appropriate for the task.

In cases where removal work generates high short-term concentrations,access to the work zone should be restricted to the removal operatorscarrying out the brushing, scraping or grinding operations. Whenever possible,the removal area should be removed or maintained wetted or treated with acoating or rigidiser. Smoking, eating or drinking should not be allowed withinthe zone. A list of authorised personnel should be posted. Waste ASW/RCFmaterials should be placed immediately into tear-resistant plastic bags, sealedand labelled “Refractory Ceramic Fibres”. These should be stored in adesignated area.

Preparation: same as for assembly, installation and removal of materials:intervention by authorised personnel equipped with P3 masks, safety glassesand appropriate gloves.

The zone should be clearly marked-off by tape or rope, accompanied by signsand a pictogram prohibiting access to persons not equipped with a type P3respiratory protective device.

ASW/RCF materials are used in the manufacture of exhaust systems.

Removal of

components

Work conducted

outdoors

Example 2

Reduction of

dust concentrations

during assembly

of an automotive

exhaust system


page 46

ASW/RCF felt provides high-temperature insulation of the catalytic convertercore. Pieces of ASW/RCF blanket, bought in pre-cut, are assembled on theceramic core.

The company described had already initiated some exposure reductionmeasures by installing down-draught tables at each of the five assemblyworkstations, but wished to reduce exposure levels further. An ECFIA hygienistmeasured personal exposures to fibrous dust on five operators over a workshift and assessed the efficacy of the control measures in use. Dustconcentrations were low overall (0.03 to 0.15 f/ ml, average 0.07).

During the measurement, several deficiencies were noted in the implementedcontrols. The recommendations were: • Improve capture velocity above one down-draught table (0.2 m/s during

the measurements) • Ensure equal distribution of air velocities above all down-draught tables to

ensure capture of dust from all sources handled • Use vacuum cleaners equipped with high-efficiency filters to clean floors

and surface instead of dry brushes • Unpack ASW/RCF pieces from boxes on the down-draught tables • Remove waste fibre from empty boxes by vacuum cleaning prior to

handling and discarding boxes • Inform workers of the risks of working with ASW/RCF and train them in

safe working procedures.


The company implemented essentially all of the ECFIA recommendations and conducted repeat measurements of personal exposures to fibrous dust 4 months later.

Dust concentrations were substantially lower than those measured initially(0.001 to 0.04 f/ml; average 0.003). In addition, the company prepared apamphlet to inform workers about ASW/RCF, state of knowledge on healtheffects, European classification, reductions of dust concentrations, along withrecommendations for limiting exposures.

Installation of

assembled

components, or

episodic intervention

on the insulation,

(e.g. maintenance)

Removal of

components


The CARE programme data presented here show that average concentrationsin fibre production, mixing-forming, and most assembly and installationoperations are below 0.5 f/ml. Average figures do not, of course, tell thewhole story. Individual applications can produce elevated exposures,especially if the appropriate control measures are not used. This guideidentifies applications where concentrations are likely to be higher than manyexposure limits and provides practical advice for limiting exposures throughtechnical or organizational means. Operations known to generate excessivedust concentrations and for which technical control measures are difficult,(e.g. furnace wrecking; certain finishing operations) will require appropriaterespiratory protective equipment. This comprehensive review, based oninternationally recognised data, allows workplace concentrations to beestimated for many situations, and technical and organisational measures tobe devised. Proper application of these measures will not only satisfy stringentEU requirements, but more importantly, protect worker health.

CONCLUSION

page 48


APPENDICES

A Expanded list of functional categories withdefinitions and examples

B Operations monitored in the primaryproduction group

C Operations monitored in the secondaryproduction group

D Operations monitored in the furnace relatedgroup

E Operations monitored in other uses group

F Trade names of RCF products for Unifrax,Rath and Thermal Ceramics

G ECFIA generic Material Safety Data Sheet(MSDS) for RCF products, refer to ECFIAwebsite

H Respirable Crystalline Silica (RCS) in after use HTIW

page 49


APPENDICES

Appendix A - Expanded List of Functional Categories with Definitions and Examples

Definition

The production or manufacture of

ASW/RCF bulk or blanket, except

in a supervisory capacity. Includes

all job functions on the production

line, from mixing the raw

ingredients to packaging the

finished product (bulk or blanket) at

the end of the line.

Cutting or machining ASW/RCF

materials after fibre manufacture.

Hand or power tools may be used

in finishing operations.

General

Examples

• Raw materials, furnace man,

furnace operator, or assistant

furnace operator.

• Production worker or relief.

• Blanket line.

• Working leader.

• Needler.

• Slit/cut/pack.

• Line utility.

• Utility operator.

• Chopper operator.

• End of line, bagging of bulk

ASW/RCF.

• End of line trimming, rolling, and

packaging of ASW/RCF blanket.

• Operating diestamp on

ASW/RCF blanket or paper

except for automotive

applications.

• Sawing, slotting, trimming, or

filing casting tips or riser

sleeves.

• Cutting blanket for ductwrap.

• Cutting or trimming ASW/RCF

board or other vacuum-formed

ASW/RCF material.

• Sanding ASW/RCF board or

other vacuum-formed ASW/RCF

material.

• Loading sander.

• Off-line cutting and tandem

rerolling and/or repackaging of

ASW/RCF blanket.

• Cutting or trimming ASW/RCF

modules for use in appliances.

• Milling or routing ASW/RCF

board or other vacuum-formed

ASW/RCF material.

• Off-site cutting of batten strips

from ASW/RCF blanket.

Functional

Category

Fibre

Manufacturing

Finishing

Additional

and Guidance

None to date.

• Working in an area

where finishing

operations are taking

place, although not

personally working with

ASW/RCF materials,

unless in a supervisory

or other “Auxiliary

Operations” capacity.

EXAMPLE: Unloading dryforms from the dryingoven and taken them tothe finishing area for finalshaping or packagingshapes immediately afterfinishing would beconsidered finishing whileunloading dry forms froman oven and taking themto be packaged, as wellas packaging shapes thatcome directly from thedrying oven would beconsidered “AuxiliaryOperations.”

page 50


page 51

Definition

Building or manufacturing industrial

furnaces or boilers, refinery or

petrochemical plant equipment,

kilns, foundries, electric power

generators, and industrial

incinerators at end-user locations,

and building large furnaces and

furnace parts at remote factories in

cases where use of engineering

controls is impractical (examples:

(1) work is performed in an

enclosed area [i.e., inside the

furnace]; (2) large size or

orientation of furnace parts

precludes application of

engineering controls.) Includes

furnace maintenance. Does not

include factory manufacture of

small industrial furnace

components when work is

performed in an open area outside

the furnace where engineering

controls would be used.

Removal of after-service ASW/RCF

material from an industrial furnace,

etc., that has completed its

economic life. Includes the removal

of ASW/RCF material in furnace

maintenance.

Combining or assembling

ASW/RCF material with other

material (ASW/RCF or other),

except automotive applications.

This includes factory assembly of

industrial furnace components

when work is performed in an

open area outside the furnace

where engineering controls are

practical.

General

Examples

• Unwrapping and knocking out

moulds.

• Furnace disassembly.

• Furnace maintenance.

• Cleanup and disposal of

removed material.

• Laminating.

• Encapsulating ASW/RCF

blanket.

• Assembling appliances.

• Off site assembly of industrial

furnace components when work

is performed in an open area

outside the furnace where

engineering controls are

practical.• Changing ASW/RCF gaskets,

etc. in appliances.• Cutting and assembling material

for sound proofing exhaustducts.

• Sewing ASW/RCF material.• Stapling ASW/RCF material.• Ball milling or grinding

ASW/RCF material.• Lamination of ASW/RCF paper.

Functional

Category

Installation

Removal

Assembly

Operations

Additional

and Guidance

Employees working inside

furnace during the removal

of ASW/RCF materials,

even though not working

directly with that material

(e.g., a plumber or

electrician working inside a

furnace during a removal).


Definition

Wet-end production of vacuum-

cast shapes, board and felt and

paper. Includes mixing ASW/RCF

mastics, compounds, or castables.

Jobs in which employees are

“passively” exposed to ASW/RCF

while performing their normal

duties and whose exposures are

not likely to parallel those of

employees working directly with

ASW/RCF materials. Includes

certain jobs in which ASW/RCF

may be handled, but with small

probability of significant exposures

(e.g., warehouse worker or person

unloading completed parts for

packaging.)

All duties performed in the

production of ASW/RCF paper,

textiles, and automotive

components or other industry

sectors not covered in any of the

foregoing categories. Also,

exposures that cannot reasonably

be included in the categories listed

above (i.e., not elsewhere

classified). IH personnel should

explain tasks and industry sectors

as fully as possible for observations

in this category.

General

Examples

• Forming ASW/RCF board or

shapes.

• Weighing, batching, or mixing

materials to be formed.

• Placing wet parts on conveyor.

• Operating mixing machine.

• Felting.

• Wet-end papermaking.

• Mixing ASW/RCF mastics,

compounds and castables.

• Driving forklift.

• Making cartons to package

ASW/RCF at end of line.

• Quality control inspection.

• Packaging dry parts.

• Maintaining or repairing

equipment except furnaces.

• Cleaning furnaces or plant areas

where ASW/RCF is used.

• Removing vacuum-formed parts

from oven and/or packaging

them (no finishing).

• Moving ASW/RCF-wrapped

moulds into and out of furnace.

• Warehouse duties, including:

Dockwork, loading trucks,

moving materials.

• Supervising.

• Diecutting parts for automotive

airbag filters, gaskets, mufflers

or catalytic converters.

• Wrapping substrate for catalytic

converter.

• Operating former to make

roving.

• Operating tape loom.

• Operating carding machine.

• End-use applications.

• Dry-end papermaking,

supervision of papermaking.

Functional

Category

Mixing/Forming

Auxiliary

Operations

Other (NEC)

Additional

and Guidance

Premixing dry materialsbefore adding to mix tank.

page 52


page 53

Appendix B - Operations monitored in the primary production group

Furnace Includes operating the fibre production furnace and mixing raw materialsNeedler Operating the needler for blanket productionBagging Packing bulk RCF

Reel End Slitting, cutting and packaging/boxing blanket, sometimes termed ‘reel end’Chopping Chopping blanket scrap

Fibre line general operation/Miscellaneous Fibre line helpers, spare men, miscellaneous fibre line workersMaintenance/cleaning Maintenance and cleaning activities associated with the fibre production lines

and equipmentSupervision Supervisors associated directly with the fibre lines and other supervisors not

directly associated with secondary productionQuality control QA/QC activities associated with bulk and blanket

Warehouse/forklift Warehouse workers handling wrapped/packaged RCF and forklift drivers in thewarehouse

Auxiliary Other workers with passive exposure, (e.g. electricians, administrative workers,production area forklift drivers) and unspecified Auxiliary workers.

Appendix C - Operations monitored in the secondary production group

Manufacturing modules All jobs connected with making modules from blanket (folding, trimming,hardware installation)

Mixing Wet mixing RCF for vacuum forming boards, shapes or paperForming Vacuum forming board, shapes and paper

Mixing and Forming Both wet mixing and forming performed on a shiftDry mixing Dry mixing bulk RCF with other ingredients (for vacuum forming or cements)

Ball Mill Ball mill bulk in preparation for mixing operationDry end paper Slitting, rolling of paper

Board saw Operate board saw (at ECFIA member plants only)Board sander Operate board sander (at ECFIA member plants only)

Board sander and board saw Operate both machines (at ECFIA member plants only)Band saw Cut various materials on a band sawCut, saw Cut various materials on a power saw (circular saw, table saw)

Die cut Operate die cutting machine, take cut productHand finishing Fishing using hand tools

Linishing Operate linisherSanding Sanding various materials with power tools

Drill, grind, router, lathe, mill Operate these power toolsWater-jet cutting Cutting with a high-pressure stream of water

Package in finishing area Package parts in close proximity to a finishing operationMultiple finishing task/misc. More than one finishing task listed, and miscellaneous samples

Laminate/Encapsulate Laminate or encapsulate RCF, (e.g. with aluminium of aluminium foil)Textiles Making RCF extile products such as rope or cloth

Assembly with RCF Primary a task that is categorised in the ‘Use’ groupsAssembly with RCF, some finishing Same as above but includes some amount of finishing work

Packaging Handling or packaging RCF productsQuality control QA/QC activities associated with manufactured RCF products

Supervision Supervision of secondary product tasksMaintenance/Cleaning Maintaining or cleaning of secondary production area or equipment

Warehouse/forklift Warehouse workers handling wrapped/packaged RCF and forklift drivers in thewarehouse for manufactured RCF products

Auxiliary Other workers with passive exposure, (e.g. welders, administrative workers,production area forklift drivers) and unspecified Auxiliary workers


Appendix D - Operations monitored in the furnace-related group

Install Install blanket, board or modules in the furnaceInstall + some finishing, Tamping Same as above but including some cutting or tamping of the RCF product

Install + other jobs Other jobs inside a furnace during installation of RCFRemove Remove after service RCF from furnace

Remove-wet Same as above, but the RCF lining is wetted before removal to suppressairborne fibre and dust

Cleanup, disposal Cleanup and disposal of removed RCF wasteCut, saw Cutting RCF blanket for installers (on-site within furnace installation)Auxiliary Passive exposure to installation or removal, supervision

Appendix E - Operations monitored in the other end-uses group

Industry Sector ActivitiesAbrasives Production of abrasive shapes and wheels

Aerospace Manufacture of components used in aerospace applicationsAluminium Primary aluminium and aluminium casting

Automotive Manufacture of automotive parts Boiler Manufacture of boilers

Domestic appliances Manufacture of domestic water heaters, ovens, and fireplace unitsFire protection Manufacture of expansion joints

Foundry Casting of metal partsGlass Manufacture of glass and glass products

Industrial ceramics Manufacture of industrial ceramics parts and refractory blocksIndustrial equipment Manufacture of various equipment such as rolling steel doors, welding shields,

sampling probes, ventilation ducting and ovens for industrial useSteel Manufacture of steels

See also Table 13.3: Other end uses

Jobs monitored in the ‘other end-uses’ group

Assemble with RCF Assembly of parts, appliances or equipment including (generally prefabricated)Assemble + some finishing As above, but including some cutting, sanding or other finishing activities

Change seal Change RCF seal periodicallyEnd use Use equipment or furnace with RCF parts, but no manipulation of RCF

Line kiln cars, moulds, ladles Install RCF on kiln cars, molds, ladles, etcKiln car, ladle removal, mould knock out Remove after-service RCF from kiln cars, molds, ladles, etc

Furnace repair ‘Spot’ repair of furnace liningMaintenance/Cleaning Maintenance and custodial activities

Packaging Packaging completed parts or equipmentQuality control QA, QC activities

Supervision Supervisors, foremen, etcWarehouse/Forklift Shipping, warehouse, and forklift operation inside the warehouse

Auxiliary Other passive exposure including forklift operation on the production floor

page 54


Appendix F

Unifrax Fiberfrax, Fiberfrax ZThermal ceramics Cerafibre, Kaowool

Rath Alsitra

Appendix G

MSDS for ASW/RCF products - refer to web site

Appendix H

Respirable Crystalline Silica (RCS) in after use HTIW

page 55

Health aspects of Crystalline Silica in devitrified HTIW, more specifically RCF and AES, have been extensivelytested.

After-service RCF have been tested in animals in long term high dose testing by intratracheal injection (IP) andby inhalation and have shown no carcinogenic effect. Heat treated AES (up to 900°C) have been tested and have shown no decrease of their biosolubility comparedto products as sold.

After-service AES have been tested in vitro on rat lung macrophage and have shown no additional toxicitywhen compared to the as sold material and have a non significant level of toxicity compared to quartz DQ 12.

Fibrosis and cancer occurrence in humans has only been observed in freshly cleaved free crystalline silica inrespirable dust.

In devitrified fibres, the crystalline silica is trapped in grain boundaries between a matrix predominantlyconsisting of other crystal formations, (mixed minerals) or glass. Furthermore devitrified fibres are more easilyremoved from the lungs due to faster breakage and clearance.

What about exposure?

Regulation does not differentiate between biologically available (free freshly cleaved) and embedded crystallinesilica. Regulation applies therefore as long as respirable crystalline silica is present in the dust.

In order to address this question the CARE programme occupational hygienists took samples in after-serviceoperations in order to evaluate crystalline silica concentrations in addition to fibre concentrations. The tablebelow (Table 12) summarises these findings of about 190 samples analysed for quartz, cristobalite andtridymite, 3 polymorph forms of crystalline silica.

• 3 measurements gave concentrations above the limit value• Source of quartz may not be coming from fibres • Excluding quartz samples over-passing the limit value one measurement remains above the limit value out of

190 samples.

Total number Number of Average Most stringent Number of % of TWA

of samples samples over the concentration limit value mg/m3 samples over the

detection limit of samples over above the limit limit value

the detection

limit mg/m3

Quartz 191 26 0.023 0.10 2 1.05

Cristobalite 187 6 0.041 0.05 1 0.53

Tridymite 163 2 0.03 0.05 0 0.00

Table 12


page 56

80%

85%

90%

95%

100%

Quartz

% o

f sam

ples

Cristobalite Tridymite

Number of samples above occupational exposure limit

Number of samples over the analytical detection limit

Number of samples below the analytical detection limit

Conclusion

IARC evaluation indicates clearly that not all occupational exposure situations or forms of CS are carcinogenic.

Animal data indicate clearly that after-service RCF do not show additional toxicity due to CS. Similarly after-service AES wools have been tested in vitro and do no show any toxicity linked with the presence of CS.Biosolubility of after-service AES is not reduced compared to as sold products and CARE data show clearlythat crystalline silica is rarely present in respirable dust from removal operations.

Crystalline silica is rarely present in dusts. It is therefore unlikely that CS levels reach levels where specificprecautions measures need to be taken. If the fibre limit value is complied to then no further measures inconnection with CS exposure are required.



3 rue du Colonel Moll, 75017 Paris, France.

Tel: +33 (0) 631 487426Email: [email protected]


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