Class II, Type A hoods are used to protect personnel, product and environment from bioaerosols and particulates. These hoods offer personnel protection through negative pressure airflow into the cabinet. To protect the product, the work area in the cabinet is continuously bathed with ultra-clean air provided through the supply HEPA filter. Approximately 70% of the air from each cycle is recirculated through this supply HEPA filter. The remaining air (approximately 30%) is discharged from the hood through the exhaust HEPA filter, protecting the environment. Although not required for the majority of uses, all of our hoods have the capability of being vented to the outside environment.

The Class II Type B2 cabinet is a Total Exhaust Vertical Laminar Flow Biological Safety Fume Hood. It was developed in order to provide protection from diverse types of biohazardous material without recirculating gases and fumes in the work area.

The conventional fume hood only protects the user. The Class II, Type A 70% recirculating hood, in addition to protecting the user, also protects work in progress and the environment from all particulates. The Class II, type B2 Biological Safety Cabinet carries this protection one step further by ducting (venting) to the outside of the building 100% of the air entering the hood. This total exhaust feature makes the B2 hood suitable for not only handling particulates, but also fumes and gases. It is especially desirable for work with radionuclides, effluents from subliming particulates and noxious odors.

The Class II, Type B2 cabinet provides 100% exhaust, with absolutely no recirculation of air in the cabinet. Other Class II, Type B units, B1 and B3, allow for the possibility of gases to be recirculated.