Biological safety cabinet vs laminar flow hood
Laminar Flow Hoods
* provide product protection only and must not be used when working with any form of biohazard or chemical hazard
* any potentially infectious aerosol that is created will lead to exposure of the operator and the environment
* horizontal-flow clean-air bench used for cell cultures can expose the researcher to aerosols of allergenic or infectious materials.
* vertical-flow clean-air bench also blows air out into the room
Biological Safety Cabinets
* provide personnel and environmental protection and commonly product protection
* infectious agents must be used in a biological safety cabinet NOT a laminar flow hood
Class I Biological Safety Cabinet
* a ventilated cabinet which provides personnel and environmental protection only
* air flow is directed away from the researcher, but is not HEPA filtered, therefore there is no product protection
* similar to a fume hood with a HEPA filter on the exhaust system to protect against the release of biohazards
* inward air flow ranges from 75-125 linear feet per minute (lfpm)
* can be used with radioisotopes and some toxic chemicals
Class II Biological Safety Cabinet
* provides personnel, product and environmental protection
* there are supply air and exhaust air HEPA filters
* two general types: IIA cabinets have a minimum inward air flow of 75 lfpm and recirculates 70% of the air; IIB cabinets have a minimum inward air flow of 100 lfpm and exhaust either 70% (type B1) or 100% (type B2)
* most of the biological safety cabinets at UVic are Class II
Class III Biological Safety Cabinet
* these cabinets provide personnel, product and environmental protection
* they are hermetically sealed and all procedures are conducted through arm-length rubber gloves
* used in high level (Level 4) containment labs
* there are two HEPA filters on the exhaust system