The Biological Safety Cabinet (BSC), which is used to manipulate infectious microorganisms, is a vital piece of safety equipment. Biological safety cabinets are the most common form of containment devised for dealing with infectious microorganisms in a safe manner. Horizontal clean benches with the user facing them are not biological safety cabinets and should not be used to treat contagious, harmful, or sensitising products. Since biosafety cabinets are built to provide both a sterile work atmosphere and security for workers who work with biological hazards, vertical laminar airflow is used to build a barrier to airborne particles, such as microorganisms. Vertical laminar air flow protects both the staff and the product. For more details view here.
For recirculation over the work area, biosafety cabinets use HEPA filtered air. Biosafety cabinets should not be confused with fume hoods because the HEPA filter extracts airborne contaminants from the air but does not eliminate chemical fumes. The Fume Hood is not a biosafety cabinet. Biosafety cabinets have an ultraviolet lamp that protects against contamination; however, because UV light cannot penetrate dust particles, another chemical disinfectant, iodophor, should be used to clean and decontaminate the work area.
Biological protection cabinets are divided into three categories:
BSCs Class I: a negative pressure cabinet with an open front. A HEPA filter filters the exhaust air from the cabinet. Personnel and environmental protection are provided by this class, but not substance protection.
The BSCs Class II cabinet has an open front and is ventilated. Inside the work room, this cabinet offers HEPA-filtered, recirculated mass airflow. HEPA filters are often used to filter the exhaust air from the cabinet. Personnel, the climate, and the product are all protected in this class.
BSCs Class III: is a gas-tight, fully sealed ventilated cabinet. Rubber gloves are used to perform operations within the Class III cabinet. When in service, a negative air pressure of at least 0.5 inches water gauge is maintained in the Class III cabinet. HEPA filters are used to pull supply air into the cabinet. Before being discharged outside of the facility, the cabinet exhaust air is filtered by two HEPA filters built in sequence. The Class III cabinet’s exhaust fan is usually different from the facility’s ventilation system’s exhaust fans.