ABC of Safety in the Biological Sciences - Basic Requirements

 

ABC of Safety in the Biological Sciences

 

 

 

BASIC REQUIREMENTS

The following gives basic recommendations for common hazards faced by a laboratory worker. It is essential that all personnel develop a thorough knowledge of these for their own protection as well as the protection of colleagues.

Laboratory Chemicals

There needs to be an awareness of the potential hazards, fire risk and toxicity associated with every chemical used in the laboratory. Material safety data sheets, provided by manufactures on request, contain safety related information. A complete list of hazardous substances and relevant safety related data is required by law, in some countries, to be kept in the workplace.1,2,5,6

All chemicals present some degree of danger because of toxicity, irritation or the flammable nature of the substance. Toxicity and irritation can be caused by inhalation, skin contact or ingestion of solid, liquid or vapour. Examples of some of the more commonly used agents and their associated hazards include the following:

  • Absolute ethyl alcohol is flammable and within one minute, after 4 litres is spilled and ignited, the ceiling temperature reaches 500oC9
  • 10 ml of isopropyl alcohol, ingested, can cause death.9
  • Chloroform and 40% formalin are volatile liquids with vapours that are highly toxic when inhaled. Both can also cause skin irritations. Formalin is also a potential carcinogen.9
  • Xylene is flammable and can cause severe skin irritations as well as central nervous system disorders.9

Handling potentially infective material

All human material should be handled as though potentially infectious, even if received in fixative. Not only may viable organisms be present because of inadequate or insufficient fixation but some agents, notably those responsible for the spongiform encephalopathies such as Creutzfeldt-Jakob disease, can withstand formalin fixation. When handling tissues always wear protective clothing comprising a long-sleeved laboratory coat or gown with elasticised wrist bands, rubber gloves and safety glasses. As well as from contact with contaminated material, infection can also occur from aerosols created by splattering or spilling contaminated fluids or simply from opening a container which may release droplets of moisture which then circulate in the air.

It is advisable for all personnel who handle fresh biological material to be immunised against hepatitis B. In addition it is recommended that personnel working with animals be immunised against anthrax and those in contact with chimpanzees be immunised against hepatitis A virus. An immunisation policy should form part of the occupational health and safety strategy for each laboratory.

The location and use of safety equipment

Panic is often the first reaction to accident induced trauma. Those who receive appropriate, regular instruction in safety procedures, including evacuation and fire drills, tend to remain calm and in control.

A safety shower should be provided within any laboratory where poisonous, corrosive or flammable chemical substances, especially strong oxidising or reducing agents, are handled regularly.10 The shower is used to dilute and remove chemicals splashed on to the body or clothing, as well as to extinguish clothing fires. The location of the safety shower should be clearly marked and all staff made aware of its location and instructed in its use. The safety shower must be checked regularly to determine that it is working correctly. If a safety shower is not available in the immediate vicinity staff should be made aware of the location of the nearest shower facility that is available for emergency use. If neither is available in an emergency a hose, fitted with a spray nozzle and which will fit at least one tap in the laboratory, can provide an alternative. The Australian Standard for safety showers recommends the provision of a minimum of 135 litres of water per minute at low velocity to avoid further damage to body tissues. Valves should require a positive action to shut off. Showers should be less than 10 metres travel distance from any point in the laboratory and have unobstructed access.11

Eye wash equipment should be provided, in the form of an eye wash bottle or continuous flow facility (see eye wash facility). The location of this equipment should be known to all laboratory personnel. Staff should also be familiar with the position, type and operation of the nearest fire extinguisher and learn what other fire and safety equipment is nearby.

Basic emergency procedures

Chemical splash to the eye12

Wash the eye immediately in gently flowing, cold water (wash bottle or continuous flow eye wash facility) for a minimum of 15 minutes. The eye must be kept open during flushing. At this time it is essential to obtain appropriate advice about any possible hazard to the eye from the chemical concerned.

Speed is crucial, a 30 second delay between the splash and the initial flush can lead to permanent eye damage especially if the victim is wearing contact lenses.

Never flush an eye with dilute acid or dilute alkali to 'neutralise' a chemical as these agents can cause more severe damage. Never wear contact lenses in a preparation area or where an eye splash is a possibility.

Chemical splash to the body12

Small splash - flush the area with cold water for a minimum of 15 minutes. Warm or hot water should not be used as this may facilitate the absorption of chemical substances through the skin. Vapour from hot water can also carry chemical particles which may be inhaled.

Large splash - wash the victim with a safety shower or hose for a minimum of 15 minutes. Clothing should be removed during and not before the shower.

For skin contamination, wash the affected area with a large volume of water for at least 15 minutes until all evidence of the chemical has been removed.

Contaminated clothing should be washed before re-use.

In case of fire or explosion13

All institutions should have a procedure to follow in case of fire occur. Personnel should familiarise themselves with the contents of the fire plan for their area. If a fire plan does not exist it becomes the responsibility of the safety officer or the laboratory manager to prepare one. Staff who receive regular (annual) training in fire safety tend not to panic in an emergency.

The fundamentals of a fire plan are as follows:

  • close the door leading to the fire
  • raise the alarm by calmly notifying the appropriate authority of the exact location of the fire or call the fire brigade
  • select the correct type of fire extinguisher for the class of fire
  • attempt to put out the fire using the correct type of fire extinguisher for the type of fire

If the fire has developed beyond the stage where it can be controlled with an extinguisher and if time allows

  • turn off all gas outlets and electrical appliances
  • close the door
  • ensure that the area is evacuated and wait for your fire team, safety officer or fire brigade to direct them to the fire

At this point your responsibility should end unless you are directed to perform some action by the fire team controller, safety officer or a member of the fire brigade.

Assembly point

A pre-designated area which does not interfere with access by fire fighters, is used as an assembly area. All personnel should remain in the pre-designated area until their names have been checked off against a staff list. One member of the staff, and a deputy, should have the responsibility for this procedure. In order to make staff aware of their responsibilities and the procedure to follow in the event of a fire, at least two practice fire safety evacuations of buildings should be performed each year.

Each member of the staff should be able to quickly answer each of the following questions:

  • Where is your nearest fire escape?
  • Is it readily accessible?
  • Is any operation of mechanics required?
  • Do you know how to operate the fire escape?

Fire extinguishers

Never use water or foam fire extinguishers on combustible metal fires or where there is live electrical equipment. If water is applied to a fire involving combustible metals (magnesium, lithium, sodium, aluminium, potassium, titanium or zirconium) it can burn rapidly and violently, becoming increasingly hotter and difficult to control. For each class of fire there is a particular, recommended fire extinguisher (see TABLE 1).

Fire extinguishers, must receive at least one annual safety check to ensure that they will work in an emergency. Safety checks are generally carried out by local fire authorities.

Allow staff to learn how to use fire extinguishers so that in an emergency they are familiar with the application.

Safety blankets
Safety blankets are suitable for use on small, contained fires and are effective in suppressing flames when wrapped around a person whose clothing is alight. They should be installed in laboratories in a conspicuous location with ready access, preferably at eye level.

Prevention

Consideration should be given to fire prevention inspections at least every three months in conjunction with practice fire evacuations at least every twelve months (two per year is preferable).

Some priorities would be to:14

  • reduce the level of combustible and flammable material to a minimum in the laboratory (supply for one day should suffice)
  • store combustible materials in purpose built storage areas and not in the laboratory
    • eliminate ignition sources where combustion might occur (install spark-proof switches in fume hoods and refrigerators, remove all naked flames from the work area wherever possible and eliminate sources of static electricity)
  • provide staff training in procedures which reduce fire hazards
  • do not use fume hoods as storage areas for flammable solvents

Points to note during a fire prevention inspection include the following:

  • clear floors, passage ways and escape routes
  • storage of flammable solvents
  • storage of combustible materials
  • clean and tidy storage areas with spaces between incompatible substances and combustible materials
  • evacuation procedures
  • fire control training
  • siting of gas cylinders
  • fully maintained and appropriate fire fighting equipment and siting of the fire fighting equipment
  • spark arresters in high risk areas
  • waste management for combustible materials and flammable solvents

 

 

 

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