Labconco Class I Enclosure Models 3980423 - Manual (Page 33)

Chapter 5: Appropriate Applications for Your Filtered Enclosure
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Suitable Applications
NIOSH (National Institute for Occupational Safety and Health, USA) has
established guidelines for chemical cartridge and HEPA filtered respirators.
Suitable applications for the filtered enclosures are based on these guidelines. As
with respirators, chemical contaminants are adsorbed or treated by carbon;
particulates, powders and biohazardous materials are filtered by the HEPA filter
before air is returned to the room. Biohazardous materials or other hazardous
solids can be used with the HEPA filtered enclosure as long as appropriate
decontamination occurs before filter changing operations. See Chapter 6 for
decontamination procedures.
Listed below are suitable applications for HEPA filters and accessory Odor
Control Carbon Filters.
HEPA Filter Applications, Suitability and
Guidelines

Biohazardous materials and hazardous solids to protect only the operator and
the surrounding environment.

Weighing of powders.

Release of particulates using a HEPA filter.

Powder or particulate procedures traditionally performed on an open bench.

The HEPA filtered enclosure provides personal and environmental protection
from particulate matter, hazardous powders and biohazardous materials.
Because room air is drawn through the enclosure during operation, this
enclosure should not be used for operations requiring sample protection from
environmental contamination.

HEPA filters are only effective for entrapment of particulate matter, hazardous
powders and biohazardous materials. Manipulations that generate gases or
vapors, i.e., toxic chemicals or radionuclides, require the use of a HEPA and
carbon filter in combination. Otherwise the enclosure should be ducted to the
outside. The surface of the HEPA filter is fragile and should not be touched.
Care must be taken to avoid puncturing the HEPA filter during installation. If
you suspect that a HEPA filter has been damaged, DO NOT use the enclosure.
See Chapter 6 for Replacing the HEPA Filter.

The HEPA filter will gradually accumulate airborne particulate matter from
the room and from work performed in the enclosure. 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. With normal
usage, the HEPA filters will last two to five years before requiring
replacement.

Each filtered enclosure is provided with a HEPA filter. For biohazardous
materials, follow the Decontamination Procedure in Chapter 6 for disposal
instructions.