Labconco Biological Safety Cabinets 34269 Series - Manual (Page 27)

Chapter 4: Performance Features and Safety Precautions
Product Service 1-800-522-7658 21
Original instructions
HEPA Filters
HEPA filters are disposable, dry-type particulate filters. The filter material or
media is typically made of borosilicate microfibers formed into a thin sheet,
in a process similar to the production of paper. This sheet is folded, or pleated
to increase its surface area. The pleats are typically held in place by beads of
glue that add rigidity to the media pack. The pack is then set into a frame, and
sealed as shown in Figure 4-1.
The HEPA filter manufacturer establishes the efficiency of the filter by
challenging it with an aerosol of known particle size. The number of particles
that penetrate the filter are quantified, and this establishes the efficiency of
the filter. Thus, the filters used in the Logic+ cabinets are at least 99.99%
efficient in removing particles 0.3 micron.
Note: The HEPA filter media is very fragile. DO NOT touch the media. If
you think the media of a HEPA filter is damaged, DO NOT USE THE
CABINET. Have the HEPA filter integrity tested by a certifier before using
the cabinet.
Note: HEPA Filters are only effective against particulate material. Gases will
pass through the filter.
Filter frame
Polyurethane seal
Between media pack
and filter frame
Filter media pack –
A continuous sheet
of filter media
Figure 4-1