Chapter 6: Maintaining Your Filtered Enclosure
Annually
•Replace the fluorescent lamps.
•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 XPert Filtered Balance System and XPert Filtered Balance Station 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
Determination of when to Replace
HEPA Filters
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
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