Biological Safety Cabinets (BSCs)

Biological Safety Cabinets (BSCs) are designed to contain aerosols generated during work with infectious material through the use of laminar airflow and high efficiency particulate air (HEPA) filtration. BSCs are considered a primary barrier and just one example of an engineering control designed to minimize exposures. Three classes of BSCs (Class I, II, and III) are used in microbiological laboratories. Open-fronted Class I and Class II BSCs are partial containment devices, which provide a primary barrier offering significant levels of protection to laboratory personnel and to the environment when used in combination with good aseptic technique.

The Class I BSC provides protection to personnel and the environment from contaminants within the cabinet. It is suitable for work involving low to moderate risk agents needing containment, but not product protection.

The Class II BSC protects the material(s) being manipulated inside the cabinet from external contamination, protects personnel and the environment. There are four types of Class II BSCs: Type A1, Type A2, Type B1 and Type B2. The major differences between the four types are the percent of air exhausted and recirculated and how the exhaust air is removed.

The gas-tight Class III BSC, or glove box, provides the highest attainable level of protection for personnel, environment, and product. It provides a total physical barrier between product and personnel. It is used when absolute containment of highly infectious or hazardous material is required.

Clean benches must not be utilized for work with biohazardous or chemically hazardous agents. Clean benches provide product protection by ensuring the product is exposed only to HEPA filtered air. Clean benches do not provide protection to personnel or the environment.

Directions for Safe and Effective Use

1. Have your BSC certified upon installation, after it is moved, after maintenance and annually thereafter.

2. Do not disrupt the protective airflow pattern of the BSC. Rapidly moving your arms in and out of the cabinet, people walking rapidly behind you, and open laboratory doors may disrupt the airflow pattern and reduce the effectiveness of the BSC.

3. Minimize the storage of materials in and around the BSC.

4. Do not place objects over the front air intake grille or block the rear grille.

5. Place a container with disinfectant and/or a sharps container inside the BSC for pipette discard.

6. Prior to Use:
   a. Turn off the UV light (if in use).
   b. Raise the sash to the proper height.
   c. Turn on the blower and light.
   d. Wipe down surfaces with an appropriate disinfectant.
   e. Let the air purge for 15 minutes.
   f. Wear the appropriate PPE.

7. After Use:
   a. Purge the cabinet's air for 5 minutes.
   b. Wipe down surfaces with an appropriate disinfectant.
   c. Remove PPE and dispose of Properly.
   d. Wash hands.
   e. You may leave the BSC running OR
   f. You may turn off the blower and light, close the sash, and turn on the UV (if in use).
    Caution: Never close the sash with the blower running.

Last Updated: November 3, 2006