Class II B1 and B2 Biosafety Cabinet: Backflow / Puffback Issues

The airflow in normal operation should always be inward through the front window. Hard-ducted biosafety cabinets are connected to the building exhaust. Of the exhaust system fails, and the cabinet is not installed and tested properly, the inflow can reverse, resulting in a puff-back or backflow. This can put the operator at risk. The video demonstrates a faulty biosafety cabinet.