Work Practices and Procedures
- Prepare a written checklist of materials necessary for a particular activity and place only necessary materials in the Biosafety Cabinets (BSC) before beginning work.
- Turn off Ultraviolet (UV) room light and BSC UV light before beginning work.
- Extra supplies (gloves, plates, media, etc.) should be stored outside BSC: material placed inside BSC may cause disruption to the airflow.
- Move arms in and out slowly, perpendicular to the face opening to reduce disruption of air curtain.
- Appropriate personal protective equipment must be worn. Lab coats must be buttoned. Gloves should be pulled over the knitted wrists of lab coat, not worn inside coat.
- Manipulation of materials should be delayed 1 minute after placing hands/arms inside BSC to allow air to stabilize and to "air sweep" arms.
- Do not rest arms on front grille. This allows room air to flow directly into the work area rather than being drawn through the front grille. Work with arms raised slightly.
- Do not block front grille with papers or materials.
- All operations should be performed at least 4 inches from the front grille on the work surface.
- Cabinet blowers should be operated at least 3-5 minutes before beginning work to allow the BSC to "purge" particulates.
- Interior walls, interior surface of the window, and the surfaces of all materials to be placed in the BSC should be wiped with 70% ethanol or other appropriate disinfectant before use.
- Plastic backed absorbent toweling can be placed on the work surface (but not on the front grille) to aid in cleanup and spill containment.
- Place all material as far back in the BSC as practical.
- Active work should flow from the clean to contaminated area across the work surface.
- To minimize frequent in/out arm movement and maintain air barrier, do not tape autoclavable biohazard collections bags to the outside of the BSC and upright pipette collection containers should not be used in the BSC nor placed on the floor outside the BSC (use horizontal discard trays containing an appropriate chemical disinfectant within the BSC).
- Potentially contaminated materials should not be brought out of the BSC until they have been surface decontaminated.
- Use techniques to reduce splatter and aerosol generation:
- Opened bottles or tubes should not be held in a vertical position.
- Hold the lid above open sterile surfaces to minimize direct impact of downward air.
- Open flames create turbulence which disrupts the pattern of air supplied to the work surface, and should not be used. If absolutely necessary, touch plate microburners which provide a flame on demand or electric furnaces are available. All flames must be off before disinfectants are used.
- Aspirator bottles or suction flasks should be connected to an overflow collection plastic flask containing an appropriate disinfectant, and to an in-line HEPA filter.
- If spilled liquid enters through the front or rear grilles, close the drain valves and pour decontaminating solution into the drain pans. After 20-30 minutes, collect the spilled liquid and disinfectant with paper towels.
- At the end of the work shift, the BSC should be surface decontaminated with 70% ethanol or dilute bleach.
Biosafety Cabinet Certifications
- All BSCs should be certified annually. If Biosafety Level 2 or higher materials are used in the BSC, the cabinet must be certified annually.
- If the BSC is relocated, it must be re-certified prior to use.
United States. Department of Health and Human Services. Primary Containment for Biohazards:
Selection, Installation and Use of Biological Safety Cabinets. Washington, D.C: U.S. Government
Printing Office, 1995.