Biosafety is the maintenance of safe conditions in biological research to prevent harm. The Centers for Disease Control (CDC) and the National Institutes of Health (NIH) established a set of biocontainment precautions to isolate dangerous biological agents. Biosafety Levels 1 through 4 provide laboratory practices and techniques to safeguard against harmful incidents. Failure to follow practices can lead to increased risk of exposure to biohazards or pathogens.
A biosafety cabinet (BSC), also called a biological safety cabinet or microbiological safety cabinet, is an enclosed, ventilated laboratory workspace for safely working with materials contaminated (or potentially contaminated) with pathogens requiring a defined biosafety level.
Biosafety Cabinet Classification
Biological safety cabinets or biosafety cabinets meet the requirements of Class I, II, or III specifications based on construction, airflow velocities and patterns, and exhaust systems, with class I being the most basic design. A BSC should be selected to meet the type of protection needed.
Before selecting and installing a BSC, it's important to have a sound understanding of the work to be done. For example, toxic chemicals should not be used in BSCs that recirculate exhaust air to the room. In those cases, a total exhaust cabinet (or Class II Type B2 cabinet) is needed.
Biosafety Cabinet Location
It's important to have a sound understanding of BSCs before installation. Location is important. Ideally, BSCs should be situated away from traffic and air currents. A 30-35 cm clearance should be provided above, behind and on each side of the cabinet to allow accurate air velocity measurement and to provide easy access for maintenance.
Biological Safety Cabinet Testing
BSCs protect the worker, product, and environment from exposure to microbiological agents, so biosafety cabinet testing should be done to assure the functional operation and integrity of each cabinet according to national or international performance standards at the time of installation, followed by annual testing by qualified technicians.
Selecting the correct type of BSC, installing it, using it properly, and annually certifying its operation are complex processes that should be done under the supervision of a well-trained and experienced biosafety professional trained on all aspects of BSCs.