Biological Safety Cabinets: Overview
Read about biological safety cabinet (BSC) operating procedures, certification, and decontamination requirements at UC San Diego.
Perform laboratory procedures that could create airborne biohazards in a biological safety cabinet.
Various laboratory procedures generate aerosols and droplets that may spread biohazardous material in the work area. Biological safety cabinets — also called biosafety cabinets or tissue culture hoods — are the primary means of containment developed for working safely with biohazardous materials.
When appropriate practices and procedures are followed, BSCs are designed to:
- Protect the worker and the environment from biological agents
- Protect the research materials from contamination
Make sure you are using a biological safety cabinet when you work with biohazards. Large equipment where biohazardous materials are used and/or stored, such as biosafety cabinets, incubators, refrigerators and freezers, must be visibly labeled with the universal biohazard symbol.
BSCs are different from chemical fume hoods and horizontal or vertical laminar flow "clean benches."
Chemical fume hoods look similar to biosafety cabinets but are not equipped with HEPA filters. Do not use them for work with biohazardous materials. They are designed solely to protect workers from exposure to chemicals and noxious gases.
Clean benches are intended to protect the research product but not the worker, and should never be used for handling biohazardous, toxic, or sensitizing material.
See BSC requirements and standard operating procedures:
Certification requirements
Annual certification requirement
Annual certification is required for all BSCs used for work with biohazards. The certification process ensures your BSC is working as designed.
UC San Diego has a preferred vendor for certification and maintenance.
- See Biological Safety Cabinets: Certification and Service Vendor for details and contact information. Arrange for service well in advance.
Biosafety Cabinets not operating correctly, under repair, or with expired certification must not be used and must be tagged as "Out of Order" by the lab or EH&S until repairs and/or recertification is completed.
Certification after moving
Because even small moves can disturb the HEPA filter, the cabinet must be certified after installation at a new location.
- Location matters. Choose a location for the BSC away from pedestrian traffic, doors, and air currents generated by room ventilation—all of which can disrupt airflow and compromise effective operation. When placing BSCs in a room, the minimum requirements are:
- 6 inches from adjacent walls or columns
- 6 inches between two BSCs
- 6 inches of space between both sides of the cabinet and 6 inches behind the BSC (to allow for service operations)
- 40 inches of open space in front of the BSC
- 60 inches from opposing walls, bench tops, and areas of occasional traffic
- 20 inches between BSC and bench tops along a perpendicular wall
- 100 inches between 2 BSCs facing each other
- 60 inches from behind a doorway
- 40 inches from an adjacent doorway swing side
- 6 inches from an adjacent doorway hinge side
For placement questions, contact ehsbio@ucsd.edu.
For biosafety cabinets, seismic restraints should be considered. Refer to Laboratory Seismic Restraints page.
Relocation or decommissioning
BSCs must be gas-decontaminated by a certified professional prior to being relocated or decommissioned.
- Contact the UC-approved vendor to arrange this service.
Related links:
Open flames and flammable gas policy
Open flames and flammable gases are prohibited in biological safety cabinets at UC San Diego.
- Read the Open Flames and Flammable Gas Policy for details.
Recommended BSC class and type
Three kinds of biological safety cabinets, designated as Class I, II and III, have been developed to meet varying research and clinical needs.
Environment, Health & Safety (EH&S) recommends Class II, Type A2 cabinets for UC San Diego facilities.
- Class II cabinets are designed to protect personnel, the environment, and the research product.The airflow velocity at the face of the work opening is at least 75 linear feet per minute (lfpm). Both supply air and exhaust pass through a HEPA filter. There are 4 types of Class II cabinets.
- Class II, Type A2 cabinets (formerly labeled Type A/ B3) have design features that make them more useful in research laboratories than other Class II cabinets. Also, if a Type A2 cabinet is vented to the building exhaust system via a properly functioning canopy (thimble) connection, it can be used with minute amounts of toxic chemicals.
Class I and Class III cabinets are rarely used at UC San Diego.
Class I cabinets do NOT protect the research product, and Class III cabinets (also called glove boxes) are maximum containtainment cabinets that require workers to wear arm-length gloves attached to a front panel.
- Contact EH&S Biosafety if your department needs one of these varieties.
Related links
Installation / moving / decontamination
Location matters
Choose a location for the BSC away from pedestrian traffic, doors, and air currents generated by room ventilation—all of which can disrupt airflow and compromise effective operation. When placing BSCs in a room, the minimum requirements are
- 6 inches from adjacent walls or columns
- 6 inches between two BSCs
- 6 inches of space between both sides of the cabinet and 6 inches behind the BSC (to allow for service operations)
- 40 inches of open space in front of the BSC
- 60 inches from opposing walls, bench tops, and areas of occasional traffic
- 20 inches between BSC and bench tops along a perpendicular wall
- 100 inches between 2 BSCs facing each other
- 60 inches from behind a doorway
- 40 inches from an adjacent doorway swing side
- 6 inches from an adjacent doorway hinge side
For placement questions, contact ehsbio@ucsd.edu.
Decontamination
BSCs must be gas-decontaminated by a certified professional prior to being moved or decommissioned.
- Contact the UC-approved vendor to arrange this service.
Certification after moving
Because even small moves can disturb the HEPA filter, the cabinet must be certified after installation at a new location.
Arrangements for this work need to be made well in advance in order for contractors to meet your schedule. The PI is responsible for contacting the contractors or vendors to schedule this work.
- Contact the UC-approved vendor to arrange this service.
Related links
Usage guidelines
- Hands-on biosafety cabinet training is available for researchers. Contact ehsbio@ucsd.edu to schedule a class.
- See Biological Safety Cabinets: Usage Guidelines for safe operating procedures.
- Biosafety cabinets are designed for one user at a time. Working in a Biosafety cabinet with more than one person at a time may interfere with the air flow which can result in breach of containment and an exposure to research materials.