Biosafety Cabinets Class I

Class I Cabinets

• Provide personnel and environmental protection, but not product protection
• Can contribute to sample contamination due to inward air flow
• Used to enclose equipment (e.g. centrifuges) or procedures (e.g. aerating cultures) that generate aerosols
• Can be ducted (connected to building exhaust system) or unducted (recirculating filtered exhaust back into the laboratory)

Class II Cabinets

• Provide protection for both samples and the environment
• Makeup air is HEPA-filtered
• Commonly used in clinical and research laboratories
• There are five types: Type A1, Type A2, Type B1, Type B2, and Type C1

Class III Cabinets

• Provide maximum protection for work with BSL-4 pathogenic agents
• Installed in maximum containment laboratories
• Gas-tight enclosure with materials entering and leaving through a dunk tank or double-door autoclave
• Gloves attached to the front prevent direct contact with hazardous materials
• Sometimes referred to as glove boxes