Biosafety cabinets, biosafety classification levels, use of personal protective equipment (PPE)

Biosafety Cabinets

Biosafety cabinets, also known as microbiological safety cabinets, are designed to prevent biological exposure to the operator and the environment, whilst providing a suitable work environment for the handling of biological agents.
These cabinets are created with HEPA (High Efficiency Particulate Air) filters that filter the air going in and out of the biological safety cabinet to prevent contamination.
Biosafety cabinets are of three types: Class I, Class II and Class III, with Class III offering the highest level of protection.

Biological agents are classified into four biosafety levels (BSL-1 to BSL-4) based on their potential health risk, the severity of disease they may cause, their potential for spreading, and the availability of preventative measures or treatments.
BSL-1 is used for agents that pose minimal potential threat to humans and the environment.
BSL-2 is for agents that can cause human disease but pose limited threat, and for which effective treatment and preventive measures are available.
BSL-3 is for agents that can cause serious or potentially lethal disease in humans, but for which treatments exist. This level includes special engineering and design features to prevent microorganisms from being disseminated into the environment.
BSL-4 is reserved for dangerous/exotic agents that pose high individual risk of life-threatening disease, which may be transmitted via the aerosol route and for which there is no treatment. This includes special containment devices or rooms within a facility designed for work with these agents.

PPE is used in biosafety to protect workers from exposure to infectious materials or other hazardous substances in the lab.
PPE includes items such as gloves, safety glasses, face shields, gowns, lab coat,s and respirators. The type of PPE used depends on the risk assessment for the task being performed.
Using PPE effectively requires proper use and disposal; for instance, gloves should be changed when contaminated, and PPE should not be worn outside the lab.
It’s important to remember that PPE is the last line of defence against exposure to hazardous substances. Other control measures, such as engineering controls (i.e., biosafety cabinets) and administrative controls (i.e., safe work policies and procedures), should be the primary methods of reducing risk.
Training in the proper use, maintenance, and limitations of PPE is important to ensure its effectiveness.