Training Programme on Safety in Chemical & Microbiological Laboratories By :- GOPAL DUTT PANDEY I/C INDUSTRIAL HYGIENE LABORATORY DIRECTORATE OF FACTORIES

Training Programme onSafety in Chemical

& Microbiological Laboratories

By :-

GOPAL DUTT PANDEY

I/C INDUSTRIAL HYGIENE LABORATORY

DIRECTORATE OF FACTORIES U.P.

Chemicals are an important part of our life. They are every where around us – in food we eat, water we drink, the consumer product we use even in the very air that we breath. These chemicals may occur naturally or they may be man made.

Chemicals have a wide range of possible health effects, Many of these effects are good, but it is important to remember that too much of any thing can be bad for you. More than three centuries ago, an early practioner of medicine said

“ All substances are poisons- only the dose separates a poison from a remedy”

If proper preacutions are not taken, any substance can pose a serious hazard and ofcourse any exposure to some chemicals may be hazardous.

How safely the body handles a given substance, depends on the followings

1- The type of substance

1. The amount absorbed2. The period of time over which it is absorbed3. The susceptibility of the person, who is exposed

to substance

HOW CHEMICALS ENTER IN THE BODY

1- By inhalation through nose or mouth

2- By absorption through skin

3- By ingestion. Pr swallowing ( if hands are not Wshed before

handling food,liquids,smoking materials)

4- By injection via broken glass, airless spray guns, needels, knives,

or other sharp instruments

Contaminants Gases

which are used in the laboratory in compressed gas cylinders. Some

gases are given off as by-products of an industrial process. Gases

readily difffuse or spread through the air at indoor temperature.

Vapours

Vapours are formed by evaporation of liquids or solids. The amount of

vapour given off depend upon the exposed surface area, the

temperature, and the vapour pressure. If the temperature of a liquid is

raised, the vapour pressure will increase, which will result in the

formation of greater amount of water

Particulates

Solids or liquid particulates suspended or dispersed in the air are called

particulates. Dusts, fumes, mist and smoke are examples

Most air contaminants have a built-in warning; they have an

odour, they cause irritation, or both. For example

Ammonia and Hydrogen sulfide

But the absense of odour does not always mean you are

safe example Carbon monooxide.

Some extremely toxic gases with prominent built-in

warning may work so quickly in high concentrations that

their warning are valueless.

Catagories

Chemical products having a concentration effect

Toxic substances having a concentration effect are characterised by close correlation between the degree of concentration of the substance in the recipient organ and the action of the substance induced in the body. With duration of exposure is relatively slight.

e.g :- Narcotic products by inhalation

Catagories….. Contd..

Chemical products having a cumulative effects

In the event of the absorption of an excessive quantity of a cumulative toxic substance, the later is excreted by the organism only slowly or partially while the non-excreted portion is deposited in the organism. In this type of exposure there is no strict correlation between the size of the dose absorbed and its effect since the effect will only be felt once the organism has accumulated a certain quantity of the substance

e.g:- glucosides of digitails


Chemical product whose effects depends on the concentration-time ratio

These toxic substances are distinguished from those having cumulative effect. The effect of these substances (E) is stricly dependent upon both i.e the concentration (c) of the substance to which the organism is exposed and the length of time (t) during which that concentration is experienced i.e E=c.t

In the exposure of such types of chemicals brief exposure to a high dose/concentration would have the same effect as several small doses experienced successively over a long period.

The alterations that take place in the recipient organ under the effect of a concentration-time substance which are not reversible within a given period of time, are not immediately apparent but may perceived suddenly only after a latent period varying from substance to substance.

In such exposures there in an accumulation not of the actual substance in the organism but of it as effectse.g:- Phosgene, chlorine, Ammonia


Chemical product having a limited concentration-time effect

In view of such toxic substances, which by inhalation excreted, matobolised or otherwise neutralised ( say p) in the organism. The above formula E=c.t may be modified to E=(c-p).t.

e.g:- the combination of sulfur with hydro cyanic acid ( highly toxic) gives thio cyanic acid ( relatively low toxic) consequently, even prolonged exposure to low concentrations of hydro cyanic acid does not in effect result in any acute form of poisoning


Chemical products having a carcinogenic effect

Carcinogenic substances are characterised by summation effect which is comparable to that of concentration-time toxic substances. Though the effects of each dose absorbed are absolutely irreversible.

The carcinogenic properties of chemical products nowadays receive the closest attention in all research laboratories. Numerous alkylating compounds have been found to be carcinogenic-at least in laboratoriy animals- and on the basis of experimental research, persons working with alkylating substances should be warned against the risks :-


Acute toxic effects

(i) Irritation of the skin and mucous membranes- the irritation may be acute or in the form of delayed reaction after a latent period of

several hours e.g Di-methyl sulphate.

(ii) Cytotoxic effects – the use of dual purpose alkylatinig substances for chemotherapy of cancer and specific secondary toxic effect on hepatopoiesis


Delayed toxic effects

(i) Teratogenic effects i.e thos which are responsible for observed

deformaties e.g derivatives of nitrogen mustered,

ethylenimine, alkyl sulphonic esters, nitrosoamines

(ii) Mutagenic effects i.e those responsible for hereditary alterations

in a gene or in the chromosomic stock e.g dialkylsulphates,

alkylalkenesulphonates, epoxides, ethylenimines,N-nitroso

compounds

(iii) Carcinogenic effects i.e those responsible for neoformation e.g

eratives of yprites epoxides, ethylenimines,

lactones,sulphones,dialkylsulphates,alkylhallides and other

simple alkylating compounds, amino-alkylating compounds,diazo-

alkenes

MICROBIOLOGICAL LABORATORY

Mode of transmission

Passage through the skin or mucous membranes

e.g use of soiled linen or clothing, contamination of conjunctivas by microscope eyepiece, projection of microbe cultures into the eyes or onto the skin, contact with animal fur

Scratches, cuts, bites and stings

e.g skin-pricks from contaminated syringe needled, cuts caused by shattered glass, small wounds received during biopsies or necropsies, animal bites and scratches, etc.

Mode of transmission…..contd….

Through the digestive track

e.g taking of meals or drinks during work, contamination of meals by insects, inadequate disinfections of hands before meals, contaminated cigarettes, lack of care in the use of protective clothing's, careless use of pipettes, nail-biting, use of make-up during work etc.

Through the respiratory tract

e.g contaminated aerosols resulting from centrifugation, dust from the cleaning of linen or clothing, which has not been dis-infected, cleaning out of animal cages, direct expectoration by sick persons or animals, projection of culture residue from culture wires that has not been properly sterilized, contaminated airborne aerosols or dust etc.

PREVENTION

There is no laboratory operation that can not be carried out in reasonable conditions of safety, but in certain circumstances such as when the work is carried out with defective equipment or when the personnel have not been informed of or ignores the inherent risks, there may indeed be a definite health hazard. While working in laboratory environment, person should give consideration given below to avoid any exposure or accident

PERSONNEL TRAININGPrevention…contd…

All the employees, including auxiliary staff must receive basic training in hygiene, epidemiology and disinfections. Each person must be properly acquainted with the dangers inherent in his work and recieve systematic training in techniques, processes and personal behaviour that are conductive to the avoidance of any infection during course of his work

Every laboratory should draw up a safety drill indicating the various precautions to be taken and distribute the copies to all employee engaged in these operations as well as display the Do's & Don't at appropriate locations

MEDICAL EXAMINATION ON RECRUITMENT AND PERIODICAL EXAMINATIONS

Prevention…contd…

Before an employee can be allowed to engage in laboratory work, he must undergo a medical examination to ensure that he is in good health, is in good physical condition, has sufficient natural resistance to work with infectious agents and should not for any reason be advised against receiving the necessary vaccinations. These examination should be repeated at intervals depending on the nature of the risk.

IMMUNISATION OF PERSONNELPrevention…contd…

All employees must receive the vaccinations laid down by regulations; moreover, the must be immunised against any diseases to which they may be exposed in the course of their work. Revaccination must be carried out at appropriate intervals.

DISINFECTION OF PREMISES AND EQUIPMENTPrevention…contd…

Disinfection covers all measures taken to destroy pathogenic germs and is of the utmost importance in microbiology laboratories were the air, floor, walls, windows, insect screens, draining boards and furniture have to be regularly disinfected. Laboratory instruments, gloves and glassware must be sterilised before use; linen must be treated with disinfectant solutions before or during washing. Biological products and contaminated waste, along with dead animals and microbe cultures, must be sterilised in an autoclave before being destroyed.

An aseptic atmosphere is achieved by means of the total destruction of germs and elimination of dust by a combination of filtering, conditioning and disinfection of the air and the use of a special ventilation system in which laminar airflow provides a regular, continuous, parallel movement casing the least possible turbulence. All walls and furniture must have smooth surfaces which can be easily and effectively disinfected. Windows must be protected by screens.

The sterilisation area must be designed for the separate sterilisation of the contaminated articles and of the clean glassware, instruments and media. Staff cloakroom must likewise be divided into a sterile part and a contaminated part, separated by a compartment fitted with showers which can be disinfected either by ultraviolet rays or by a disinfectant spray.

PLANING OF PREMISESPrevention…contd…

PERSONAL HYGIENEPrevention…contd…

(a) before starting work: remove clothing and shoes, place them in the

"sterile" cloakroom, enter the "contaminated" cloakroom and put on

work clothes.

(b) work clothes: to be worn only in the "contaminated" sector and

never exchanged between colleagues;

(c) after every direct contact with the infectious equipment: carefully

disinfect hands by washing them in the appropriate solution for the

prescribed length of time allowed by washing in running water with

a disinfectant soap; never touch the soap or towel with hands which

have not been disinfected; never use another person's towel;

(d) before leaving the "contaminated" sector: disinfect and wash hands

carefully, disinfected shoes on the mat, remove at least the outer

"contaminated" coat and disinfect and wash the hands once again;


Personnel Hygiene…. Contd….

(e) at the end of work or before taking meals in the canteen or dining room,

in addition to the precautions listed above; remove all work clothes in

the "contaminated" cloakroom, disinfect hands, take a shower and

enter the "sterile" cloakroom to put on normal clothing;

(f) for any work liable to infect the hand use rubber gloves or tweezers; if

circumstances require, wear rubber shoes and an apron; when working

with airborne microbes, use a mask;

(g) never drink, eat or smoke in the laboratory:

(h) do not bite nails, rub the eyes or touch the face with soiled hands; while

working;


Personnel Hygiene…. Contd….

(i) disinfect and wash hands before blowing one's nose;

(j) use only disposable sterile handkerchiefs;

(k) keep hand towels used in the "contaminated" sector carefully

separate from those used in the "sterile" sector;

(l) do not take any library journals or books into the

contaminated sector; disinfect documents and notes before

removing from the "contaminated" sector.

ALWAYS CONSIDER Ventilate the work area properly when working with

chemicals. Wear appropriate protective clothings such as

gloves,aprons,safety glasses and face shield, wherever required.

Store acids separately from bases, solvents and certain other toxic material.

Know the reactions that will occur when substances are mixed to avoid an explosion or release of toxic gases.

When working with chemical substances, proper attention must be given not only to their toxicity but also to the other risks involved according to the MSDS of the particular chemical.

ALWAYS CONSIDER…CONTD..

When working with laboratory glassware, there is always the danger of broken glass, avoid it. Dangerous substances should only be handled under a ventilation hood.

For operations carried out in vacuum , the equipment must be specially designed.

The distillation of inflammable liquids in glass flasks with a nacked flame may be responsible for serious burns. This operation must always be carried out with a steam or oil bath or a suitable electric device.

Connecting up and disconnecting portable compressed bottles, which are used for laboratory operations, are frequent cause of accidents or intoxication. Gas bottles must be handled with utmost care and should always be refilled with the same gas.

ALWAYS CONSIDER…CONTD..

The washing process of glass equipment, to remove the chemical product adhering to the walls of the glass containers with the help of solvents ( which themselves are toxic) must be avoided and should be done under a ventilation hood and with protective gloves.

Where the glass equipment is used to hold toxic substances, laboratory personnel must be entrusted with the washing only if qualified members of the staff have previously washed out the contaminated equipment.

It should be an absolute rule that adolescent must not be authorised to work with highly toxic substances except under supervision of a qualified, experienced and responsible person.

The pregnant women should avoid involving them to such exposure, even at all if required special preacutions should be taken by them.

FEW SAFETY PRECAUTIONSUSE OF SYRINGES AND NEEDLES

DO'S

use glass syringes which can be sterlised in an autoclave or disposable syringes;

before and after injecting an animal, carefully disinfect the skin and hairs around the injection area;

immediately after using a syringe fill it with and place it in a disinfectant solution; use only a pad soaked in disinfectant to remove excess liquid;

Don'ts

never use glass syringes which is not sterlised in an autoclave

FEW SAFETY PRECAUTIONS… contd…

PIPETTESDO'S

plug pipettes with cotton wool;

place pipettes in a disinfectant liquid immediately after use.

DON'TS

never suck or blow in pipettes;

CENTRIFUGATION

DO'S

examine tubes after ever centrifugation for cracks;

examine the inside of the support in which the tubes are placed

after each centrifugation;

disinfect and clean the supports regularly;

always use a pipette for decanting;

DON'TS

never fill centrifugation tubes completely;


FREEZERS AND THERMOSTATSDO'S

disinfect and clean freezers and thermostats period ically;

when doing so, use gloves and protective respiratory apparatus.

HANDLING OF CULTURES

DO'S

before destroying cultures, always sterilise in an autoclave (at least

20 minutes at 1200 C and 1 atmosphere super pressure).

DON'TS

do not wet the cotton wool stopper when in shaking the culture

medium;

Never sterilise spatula and culture wires in naked flame;


HANDLING OF ANIMALSDO'S

persons working in the area where the animals are kept must always wear protective clothing and footwear; employ only persons who are highly skilled in the handling of inoculated animals.

DON'TS Never handle animals which are liable to struggle without wearing, gloves, bibs and glasses;TRANSPORT OF LABORATORY SAMPLES

DO'S the packaging used for the transport of samples must comprise an inner container in which the sample is placed and a strong outer container. Between the two a sufficient quantity of absorbent material must be placed to catch any liquid that may be spilt in the event of the breakage of the inner container. The inner container must be designed so as to prevent any outside contamination during handling;

INDICATIVE LIST OF CARCINOGENIC SUBSTANCESDeveloped by ILO Pannel of Consultants on Occupational Cancer

GROUP-1 CONTACT SHOULD BE AVOIDED

2, NaphthyleamineNitrosoamine ( Dialkyl)Benzidine4-Aminodiphenyl2- Acetylaminofluorene

2- Nitronephthylamine4- Dimethylaminoazobenzene4-NitrodiphenylMethylnitrosourea (MNU)Bis(chloromethyl) Ether

GROUP-2EXPOSURE SHOULD BE LIMITED THROUGH THE

APPLICATION OF STRINGINT PROTECTIVE MEASURES1-NaphthylaminePropane SultoneAsbestosVinyl ChlorideIonising Radiation and Radioactive Substances

Methylcholoromethyl EtherDiazomethane1,1-dimethylhydrazineBenzenebeta-propiolactone

GROUP-3EXPOSURE SHOULD BE KEPT TO A MINIMUM THROUGH THE USE OF MOST FEASIBLE AND

APPLICABLE CONTROLS

Inorganic ArsenicNickle Carbonyl4,4`-Methyl-bis-o-choloroaniline (MOCA)Dimethyl Sulphate3,3`-Dicholorobenzdine

o- toludineDianisidineEthyleneamineEthylenethiourea

MINERALS OF COMPLEX COMPOSITIONS WHOSE USE REPRESENTS A SIGNIFICANT CARCINOGENIC RISK – EXPOSURE SHOULD BE KEPT AT A MINIMUM THROUGH THE USE OF TECHNICAL AND PERSONAL PROTECTIVE MEASURES.

Coal TarHigh boiling petroleum residueCutting Mineral OilShale Oil

Cresote OilCoal PitchSoot

INDUSTRIAL PROCESSES INVOLVING SIGNIFICANT CARCINOGENIC RISK - EXPOSURE SHOULD BE KEPT AT A MINIMUM THROUGH THE USE OF MOST FEASIBLE AND APPLICABLE CONTROLS.

Treatment of Chromium oresTreatment of Nickel oreAuramine ManufactureMagenta ManufactureHematite mining

Coke-oven operationManufacture of isopropyl alcohalPressing of paraffin wax from petroleumUse of anti oxidants and accelerators in the rubber and cable making industry

CHEMICALS AND GROUP OF CHEMICALS CARCINOGENIC TO HUMANS

Chemicals and Group of Chemicals Main Target Organ

4, Aminodiphenyl Bladder

Arsenic & certain arsenic compounds Skin,Lungs

Asbestos Lung, Pleura, Gastrointestinal Track, larynx

Benzene Marrow ( Lukemia)

Benzidine Bladder

N,N-bis-2chloroethyl-2-nephthylamine Bladder

Alkylating agents like Methyl Iodide, B-propiolactone,Diethyl Sulphate,Propane Sultone Bis-choloromethyl ether & tech.Gr. choloromethyl ether

Lung

Chromium & certain chromium compounds Lung

alfa & beta Nephthylamine Bladder

Soots, tars, and mineral oils Skin,Lung,Bladder

Vinyle Chloride Liver,Lung,CNS,

Cyclophosphamide Bladder

Aromatic amines Bladder, Lung

Alkyl derivatives of Polycyclic Hydro Carbons Stomach, Lung

Oil Mist, Solvents, Dyes, Cadmium,& Lead Buical cavity, Rectum, Pancreas, Lung, Prostate,Kidney

THINGS TO REMEMBER

In case of contact flush the affected skin or eye (lifting

lower and upper lids) areas with cool water for at least

fifteen minutes. Do not rub !Move an inhalation victim to fresh air immediately. If breathing has stopped or obstructed administer

artificial respiration. Seek Medical Attention.

Know the effects of the chemical with which you are

working.

Use appropriate controls and work practices.

Learn the location and use of emergency

equipment.

THANK YOY FOR HEARING PATIENTLY

G.D.PANDEY

Documents

Training Programme on Safety in Chemical & Microbiological Laboratories By :- GOPAL DUTT PANDEY I/C INDUSTRIAL HYGIENE LABORATORY DIRECTORATE OF FACTORIES