Biosafety Cabinets- Definition, Classes (I, II, III) and Types


Biosafety cabinets (BSCs) are enclosed, ventilated laboratory workspaces for safely working with materials contaminated with (or potentially contaminated with) pathogens requiring a defined biosafety level. BSCs are also called biological safety cabinets or microbiological safety cabinets. BSCs first became commercially available in 1950.

BSCs are one type of biocontainment equipment used in biological laboratories to provide personnel, environmental, and product protection. Most BSCs (e.g., Class II and Class III) use high efficiency particulate air (HEPA) filters in both the exhaust and supply system to prevent exposure to biohazards.

The primary purpose of BSCs is to protect the laboratory personnel and the environment from the pathogenic microorganisms as aerosols might be formed during the processing of such microorganisms. All exhaust air is HEPA-filtered as it exits the biosafety cabinet, removing harmful bacteria and viruses.

BSCs are different from laminar flow clean benches, which blow unfiltered exhaust air towards the user and are not safe for work with pathogenic agents. Neither are most BSCs safe for use as fume hoods, which fail to provide the environmental protection that HEPA filtration in a BSC would provide.

BSCs are classified into three classes by the U.S. Centers for Disease Control and Prevention (CDC), each with specific performance characteristics and applications. These classes and the types of BSCs within them are distinguished by the level of personnel and environmental protection provided and the level of product protection provided.

The use of BSCs or other such physical containment is not required in the biosafety level 1, but depending on the risk assessment, some processes might require such containment. BSCs are an essential part of biosafety as they minimize the formation of aerosol, protecting the environment, the pathogen, and the laboratory personnel. Besides, most BSCs also function to sterilize biological materials that are kept inside the cabinets.