Biological Safety Cabinets Clinical Microbiology Review 138
CLASS DESCRIPTION USE
I
II
III
Provides minimal personnel protection. Doesn’t protect
work surface.
Type most commonly used in hospital micro labs. Provides
protection for worker & work.
Provides maximum protection. Used in labs that work with
extremely hazardous organisms.
Open front. Unsterilized room air enters. Air passes through high-
efficiency particulate air (HEPA) filter before being exhausted.
Laminar flow cabinets with variable sash opening. Air passes
through 1 HEPA filter before reaching work surface & 2nd one
before being exhausted.
Completely enclosed. Negative pressure. Air is filter sterilized
coming in & going out. Gloves are attached to front.
