Biological Safety Cabinets

researcher working in a biosafety cabinet

 

Updated June 28, 2024

Biological safety cabinets (BSCs) are used to protect personnel, products and the environment from exposure to biohazards and cross contamination during routine procedures.

Classes of biological safety cabinets

When choosing a biological safety cabinet for your work space, Environmental Health & Safety (EH&S) can help you select the class of cabinet that will provide the best protection.

There are three classes of BSCs: Class I, II and III. While all three classes afford personnel and environmental protection, only Class II and III cabinets provide product protection.

  • Class I BSCs are suitable for work involving low to moderate-risk agents. Since incoming air is not filtered, Class I BSCs should not be used with research materials (e.g., cell lines) that must be handled under sterile conditions. Class I cabinets are used to enclose equipment (e.g., centrifuges, harvesting equipment or small fermenters) or procedures with potential to generate aerosols (e.g., cage dumping, tissue homogenization or culture aeration). Because outgoing air is filtered, research personnel are protected while using a Class I BSC.
  • Class II BSCs provide a partial barrier for the safe manipulation of low, moderate and high-risk microorganisms. Class II cabinets, which are the most frequently used in research and clinical laboratories, are divided into four types (Types A1, A2, B1 and B2).
  • The Class III BSC is a totally enclosed, gas-tight ventilated cabinet, and provides the highest level of personnel, environmental and product protection. Operations within a Class III BSC are conducted through attached rubber gloves.

Selecting a biological safety cabinet

When purchasing a biological safety cabinet, you should consider the type of work that will be conducted in it.

Table 1 describes the principal characteristics of all classes and types of BSCs.

BSC CLASS/TYPE

PRODUCT PROTECTION

MINIMUM FACE VELOCITY (FPM)

VOLATILE TOXIC CHEMICALS, GASES OR RADIONUCLIDES ALLOWED?

I

No

75

No

II / A1*

Yes

75

No

II / A2

Yes

100

No, unless thimble connected to the HVAC system, then low levels of volatile toxic chemicals allowed

II / B1

Yes

100

Yes: low levels of volatile toxic chemicals & trace radionuclides

II / B2

Yes

100

Yes: volatile toxic chemicals & radionuclides

III

Yes

N / A

Yes

Table 1: Characteristics of different classes and types of BSCs
*These cabinets are obsolete; no parts are available to repair the cabinet.
 

For more information, please read the Chemical Use in Biological Safety Cabinets Focus Sheet.

What you need to know

Contact EH&S if you plan to purchase or relocate a biological safety cabinet, or bring a unit to the UW from another university. EH&S can help you select the appropriate cabinet for your research, evaluate the space you are considering, and determine if necessary ventilation and utilities are available. Review the Steps to Purchase, Replace, Relocate or Remove a Biosafety Cabinet for more information.

Your cabinet needs to be tested and recertified annually by a qualified EH&S safety professional. If EH&S has your cabinet in its inventory, we will contact you about a week in advance of our service.

If your cabinet sounds an alarm or does not appear to be functioning as intended, stop your work and contact EH&S for assistance.

 

Services available

EH&S provides the following services:

  • Performs certification service for biological safety cabinets to verify and assure proper performance; BSCs are tested to manufacturer's specifications and to National Sanitation Foundation Standard 49.
  • Maintains design standards for new construction and provides consultation on cabinet selection, performance, decontamination, relocation and design.
  • NSF required Gaseous Formaldehyde decontamination of the cabinet prior to service, relocation or surplus.

Frequently asked questions