Microbiological Safety Cabinets
Types of Microbiological Safety Cabinets
Class I
Class I cabinets provide worker and environmental protection, but no product protection. Air drawn across the interior work surface is not HEPA filtered. There is a HEPA filter in the exhaust system to protect the environment. Air is exhausted to atmosphere outside of the building, or re-circulated back into the room dependent on the type of work to be done in the cabinet.
Class II
Class II biological safety cabinets provide personnel, environmental and product protection. Both room air and interior cabinet air are drawn into a front grille creating an air barrier that provides personnel protection. In addition, downward laminar flow of HEPA-filtered air provides product protection. Air is exhausted to atmosphere outside of the building, or re-circulated back into the room dependent on the type of work to be done in the cabinet.
Class III
Class III biological safety cabinets provide personnel, environmental and product protection. Air is drawn through a HEPA filter located at the side or rear of the cabinet. A totally enclosed cabinet in which operations are conducted through gloves attached to glove ports. Air is exhausted to atmosphere outside of the building, or re-circulated back into the room dependent on the type of work to be done in the cabinet.
Test Procedures
- General checks will be made on the condition of any pre-filters within the workstation. The functions of the workstation will be checked for correct operation.
- Airflow readings are taken for microbiological safety cabinets, measurements taken with a vane anemometer, in accordance with BS EN 12469: (2000).
- Filter integrity leak tests will be carried out on all HEPA filters in accordance with BS EN ISO 14644-3 (2005).
- Airborne particulate cleanliness counts will be carried out in accordance with BS EN 14644-1 (1999), and EU GMP Annex 1 (February 2008) (optional test).
- KI discus operation protection test in accordance with BS EN 12469: (2000) (optional test).