Biological safety cabinets provide personnel, product and environmental protection from hazardous particulates and agents that require biosafety level 1, 2 or 3 containment. Type A2 Biological Safety Cabinets are the most used around the world which stands around 90% of the Biological Safety Cabinets. The airflow of the cabinet is 30% exhausted through Exhaust HEPA filter whereas the remaining 70% of the air is recycled through Downflow HEPA filter within the biosafety cabinet A2. This filtered exhaust air can be externally extracted with a thimble system, direct duct or simply extracted back into the laboratory. However, if volatile chemicals are used within the A2 biosafety cabinet as an adjunct to microbiological work, exhaust must be released into the atmosphere through a thimble system or direct duct. The biosafety cabinet A2 is suitable for working with microbiological research in the absence of volatile or toxic chemicals and radionuclide.