Laboratory Biosafety Cabinets (GMP)

About Laboratory Biosafety Cabinets (GMP)

PSI Class II Bio safety Cabinet TypeA2 are designedfor protection of operator, product and environment from pathogenic agents andmicroorganisms transmitted in respiratory way and also for creation of abacterial dust free air environment. It has a common plenum from which 30% ofair is exhausted, and 70% re-circulated to the work area as the down flow. TypeA cabinets exhaust air directly back to the laboratory, and they may containpositive pressure contaminated plenums. When toxic chemicals must be employedas an adjunct to microbiological processes, these cabinets should not be used.Exhaust HEPA filtration only removes airborne aerosols including biohazards,and not chemical fumes.

The Class II Type A2 that has a negative pressuresurrounding the positively pressurized contaminated plenum. In case there is aleakage on the positive plenum, the leaking aerosol will be pulled by thenegative pressure back to the positive plenum, and it will not leak out.Because of the safety issue, the Type A1 design is now considered obsolete. Inthe A2 cabinet, about 70% of air from the positive plenum is recirculated asdown flow, and the remaining