EHS - Biological Safety Cabinets


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Class II Biological Safety Cabinets

Class II biological safety cabinets provide personnel, environmental and product protection. Air drawn into the cabinet passes through a high efficiency particulate air (HEPA) filter before it passes over the work surface. Class II biological safety cabinets are further broken down into types A1, A2, B1, and B2.

The class IIA cabinet recirculates approximately 70% of its air flow within the cabinet. This cabinet exhausts into the room or through the building exhaust by a canopy unit. (See Figure 1 and Figure2)

Figure 1: CLASS II TYPE A1 BIOLOGICAL SAFETY CABINET
(Can be room re-circulated or air gap type (thimble).)

Figure 2: CLASS II TYPE A2 BIOLOGICAL SAFETY CABINET
(Can be room re-circulated or air gap type (thimble).)

Class II Type B1 cabinet recirculates approximately 30% of its air flow within the cabinet. This cabinet exhausts to the outside through a duct system. (See Figure 3)

Figure 3: CLASS II TYPE B1 BIOLOGICAL SAFETY CABINET
(Hard-ducted.)

The class II Type B2 cabinet does not recirculate any air within the cabinet. All exhaust leaves the cabinet through a duct to the outdoors. (See Figure 4)

Figure 4: CLASS II TYPE B2 BIOLOGICAL SAFETY CABINET
(Hard-Ducted.)

For further information, questions, or help in selecting the proper cabinet for your application please contact Kathleen Schmidt or call 831-3123.