Wayne State University

Biological Safety Cabinets


Annual Biosafety Cabinet (BSC) certification:

  • BSCs must be certified annually by OEH&S. We provide a centralized system to record and track certifications and repairs.
  • If there is a filter change, a move, or if at anytime you suspect it's not working properly or the cabinet is past due for its annual certification, contact Tim Droze, Environmental Health Technician at 313-577-0068 or bb9984@wayne.edu.
  • What is covered?
    • Testing and certification services are no Charge from OEHS.
    • Analysis of Unit for Repair or Replacement
    • Price Quote for parts/delivery
    • Price Quote for service
  • What is NOT covered?
    • Repairs, expendable parts (e.g. HEPA filter changes, motors, light tubes, etc.), and labor
    • Gas decontamination (if necessary for repairs or a HEPA filter change)
    • Replacement of motor, electrical system, or structure of the BSC
  • To submit an online request for certification of your biosafety cabinet, see this link:


General suggestions:

  • Keep your laboratory meticulously clean. Minimize storage of boxes and supplies, particularly near the BSC.
  • Wash your hands thoroughly before and after working in the BSC. Wear a clean lab coat and gloves while working in a BSC to protect yourself and to reduce contamination of research materials.
  • The effectiveness of the BSC is a function of directional airflow (inward and downward) through a high efficiency particulate air filter (HEPA). Anything that disrupts the airflow pattern reduces the cabinet's effectiveness.
  • Rapid movement of your arms in and out of the BSC, down drafts from ventilation systems, open lab doors and improper placement of equipment and materials inside of the cabinet can all affect its function. Even rapidly walking by the cabinet will affect the airflow patterns.
  • Understand how the cabinet works and plan your work carefully. Protect yourself, your research and your coworkers by using the BSC properly.

Operational suggestions:

  • Turn on the BSC and wipe the work surface clean with 70% ethanol. Wipe off each item you need for your procedures and place them inside of the cabinet. Allow the cabinet to run for at least five minutes before beginning your work.
    • Do not place objects over the front air intake grille, and never block the rear exhaust grille.
    • Perform all work at least six inches back from the front air intake grille.
    • Arrange materials to segregate contaminated items from clean ones. Minimize movement of contaminated items over clean items. Remember to always "work from clean to dirty".
  • Put on a clean lab coat, wash hands thoroughly and use clean, latex gloves.
  • Follow good microbiological techniques:
    • Hold open tubes and bottles as horizontal as possible.
    • Use mechanical pipetting devices. Never pipette by mouth!
    • Use horizontal pipette discard pans containing the appropriate disinfectant inside the BSC. Do not use vertical pipette discard canisters on the floor outside of the cabinet.
    • It is not necessary to flame items. This can create turbulence in airflow and will compromise sterility. Heat buildup may also damage the filters.
  • If you need to remove items from the BSC or introduce new items, move your arms slowly in and out of the cabinet in a manner that will minimize the disruption of airflow.
  • If you use a piece of equipment that creates air turbulence inside the BSC (such as a centrifuge, blender or sonicator), place the equipment in the back 1/3 of the cabinet, and stop other work while the equipment is operating.
  • Protect the building vacuum system from biohazards by placing a cartridge filter between the vacuum trap and the source valve in the cabinet.
  • Clean up spills immediately. If possible, wait 3-5 minutes before resuming work.
  • Remove all materials and wipe all interior surfaces with 70% alcohol when your work is finished. Let the cabinet run for 10 minutes before turning it off. Examine the tray under the work surface, and clean and disinfect it as necessary.
  • To collect liquid biohazardous waste, aspirate liquid into a flask containing bleach (A) connected to a second overflow collection flask (B) and separated from the vacuum system (D) by an in-line filter (C). Biohazardous liquid waste needs to be properly neutralized before disposal. Source: Biosafety in Microbiological and Biomedical Laboratories, 5th Edition








Frequently Asked Questions about Biological Safety Cabinets (BSCs)

Who do I contact about getting a BSC?
Contact Wayne State University Office of Environmental Health and Safety  313 993-7597

What type of BSC do I need?
The type of BSC needed is determined by the type of material that you wish to use in the BSC.  Contact OEHS (313-577-1200) if you are unsure about the type of BSC you need.

A Class II, A2 Biosafety Cabinet is recommended and the most common type of BSC in use, as it is appropriate for most bio-hazardous work applications. Class II BSC provide personnel protection from bio-hazardous materials using HEPA filtered air prior to release into the room, in addition to providing product protection (to maintain sterility).  Information on specific classes and types of Biosafety Cabinets can be found at http://www.cdc.gov/biosafety/publications/bmbl5/BMBL5_appendixA.pdf

Should my BSC be hard ducted or thimble connected to the building exhaust system?

Contact OEHS (313-577-1200) before having any BSC connected (or disconnected) to the building exhaust system. 

Are the UV lights in my BSC effective as a secondary disinfectant?
Ultraviolet (UV) lamps are not recommended in BSCs nor are they necessary. If installed, UV lamps must be cleaned weekly to remove any dust and dirt that may block the germicidal effectiveness of the ultraviolet light. The lamps should be checked weekly with a UV meter to ensure that the appropriate intensity of UV light is being emitted. UV lamps must be turned off when the room is occupied to protect eyes and skin from UV exposure, which can burn the cornea and cause skin cancer. If the cabinet has a sliding sash, close the sash completely when operating the UV lamp.
Reference: http://www.cdc.gov/biosafety/publications/bmbl5/BMBL5_appendixA.pdf

Can I use a clean bench for biohazardous work? Laminar Flow Cabinets, sometimes referred to as Clean Benches, may be used for work with materials that are non-infectious. No infectious work (human cell lines, infectious microorganisms, toxins, or animal work) should be performed in Laminar Flow Cabinets. They are not recommended for infectious work, as they provide only product protection, and in effect, blow air from the cabinet into the user’s face providing no personnel protection.

Why must my BSC be certified?
BSC are the primary containment device used to protect the worker, product and environment from exposure to bio-hazardous agents. The accepted standard is the NSF 49, which overall, serves to validate the design, operation, and testing of biological safety cabinets. The purpose of testing and certification is to ensure the balance of inflow and exhaust air, the distribution of air onto the work surface, and the integrity of the cabinet1.

How often must my BSC be certified?
BSC must be certified at the time of installation and annually thereafter. The BSC must be re-certified after it has been moved or when repaired (e.g., HEPA filter replacement).

What if I need to get my BSC repaired?
Contact OEHS at 313-993-7597 to schedule repairs, or submit a request here:


Does my BSC need to be decontaminated?.  Prior to certification, all work surfaces are to be cleaned with an appropriate disinfectant before servicing. Remove all equipment, sharps and waste from the BSC.

How do I get my BSC gas decontaminated?
Decontamination of the BSC using a gas decontamination method (e.g., para-formaldehyde gas) may be necessary based on the agents used. Contact OEHS for a risk assessment. Perform surface decontamination of all work surfaces (including grilles, drain pan, inside of sash, etc.) with an appropriate chemical disinfectant. Remove all equipment, sharps and waste from the BSC.

What if I need to move or dispose of my BSC?
The BSC must be gas decontaminated prior to being moved, stored, or disposed of in order to protect personnel from any potential exposure to biohazardous materials. Once decontaminated, OEH&S will provide the lab with a document certifying that the unit is ready to be moved.

Contact Facillities Planning & Management at 313-577-5307 to move the unit once it has been cleared by OEH&S. If moving to a new location, the BSC must be re-certified in the new location prior to use.