Laboratory workers are particularly exposed to chemical and biological agents. The exposure of the human body to harmful chemical substances can lead very serious occupational health issues because, as bacteria, viruses, fungi and parasites are usually invisible to the naked eye, employers and workers alike tend not to take the risks that they pose to human health into account.

What are the risks for chemical and biological laboratory workers?

The risks in a chemical laboratory are to be carefully and continuously assessed and linked to the choice of appropriate work practices in order to prevent harmful consequences. There are a few basic rules behind all work activities that should always be considered before starting work i.e.:

• determine the potential risks associated with experiments before starting;
• minimize exposure to chemical substances, preventing them from coming into contact with the skin by using laboratory chemical hoods, ventilation devices and respiratory protective devices;
• not underestimate hazards and risks;
• be prepared, in case of accidents and before starting experiments, to identify all the steps to be taken in case of accidental release of dangerous substances;
• know the location of all the safety equipment and the nearest fire alarm;
• keep the telephone numbers to call in case of emergency or accident always close at hand;
• be prepared to provide basic, temporary but effective emergency treatment.

In a biological laboratory the levels of safety, called Biological Safety Levels or BSL, are ranked from one to four and are selected based on the agents or organisms that are being researched or worked on in any given laboratory setting. Consequently, it is very important to assess the appropriate protection category depending on the level of risk.

How to protect the respiratory system

Chemical and biological laboratories should be provided with appropriate respiratory protective devices (RPD) for protection against the inhalation of hazardous substances, i.e. chemical products, inorganic vapours and infectious particles. There are different respirator types and models available and the choice depends on the results of the assessments of company processes, products and airborne hazardous substances performed by health and safety personnel or occupational hygienists.

The two types of RPD that are commonly used in the workplace are filtering devices or breathing apparatus. PAPRs are equipped with blower units run by rechargeable batteries which supply filtered air to the inside of the facepiece. Non-powered negative pressure respirators are of more simple design and are usually equipped with filters for protection against particulates and, therefore, do not protect against chemicals, gases and vapours, for which face masks, equipped with combined cartridges to filter out specific chemicals or biological substances, are more appropriate. There are filters available that protect against more than one substance, but they do not protect from all substances, so it is important to know what the workplace hazards are in order to ensure appropriate filter selection.