Biosafety cabinets are closed circuit devices designed to protect work carried out in open environments from contaminants present in ambient air, while also protecting the environment and the user from contaminants that may arise from the work itself. They operate with a sterile, laminar airflow system.
Class II A2 Biosafety Cabinets draw air from the surrounding environment and, through HEPA filters installed within the unit, remove dust, microorganisms, and similar contaminants, returning the air to the environment in a sterile condition.
Air entering through the front working glass opening is drawn in through grilles located behind the glass and directed under high pressure to the downflow HEPA filter plenum. As the air passes through these filters, it is sterilized and then supplied to the working area in a laminar flow at a velocity range of 0.3 m/s to 0.6 m/s.
The air supplied to the working area is re-extracted through grilles within the chamber. Approximately 70% of this air is recirculated back to the downflow filter plenum and included in the circulation cycle. The remaining portion is directed to the exhaust HEPA filter. After being purified from contaminants generated during the work process while passing through the exhaust filter, the air is released back into the environment in a sterilized state.
