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Chapter 6: Maintaining Your Filtered Enclosure
Annually
• Replace the fluorescent lamps. Replace UV lamps if
equipped.
• Have the enclosure validated by a qualified certification
technician. See Certification and Recertification in Chapter
6.
• All monthly activities.
Decontamination When used in conjunction with biohazards, the Purifier Class I
Enclosure and Purifier HEPA Filtered Enclosure should be
decontaminated with formaldehyde gas before:
• maintenance work in contaminated areas
• HEPA filter changes
• moving the cabinet to a new location
• changing research programs
• after a gross spill of biohazardous material
The procedures for performing a gaseous decontamination are
thoroughly outlined in the U.S. Department of Health, Education
and Welfare booklet entitled Formaldehyde Decontamination of
Laminar Flow Biological Safety Cabinets, available from NIH,
Division of Safety, Bethesda, MD 20892, call 301-496-2801, or
from Labconco Corporation.
The HEPA filters in the filtered enclosures gradually accumulate
airborne particulate matter and powders from the enclosure and
room. The rate of accumulation will depend upon the cleanliness
of the room air, the amount of time the enclosure is operating, and
the nature of work being done in the enclosure. In typical
installations and usage, the HEPA filters will last two to five years
before requiring replacement. Replace HEPA filters when face
velocity drops below the recommended 75-105 fpm velocity, and
the speed control is adjusted to full speed. Replace HEPA filters if
it fails the HEPA Filter Leak Test in Chapter 6.