Labconco Cell Logic A2 User Manual page 40

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 5-3.
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. The HEPA filters used in the
biosafety cabinet are at least 99.99% efficient in removing particles 0.3 micron.
Figure 5-3
Filter frame
Polyurethane seal
between media pack
and filter frame
Filter media pack
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 and vapors will
pass through the filter.
ULPA Filters
Optional ULPA filters may be used to replace the standard HEPA filters in this product.
ULPA filters have the same properties as described above except they are rated at least
99.999% efficient in removing particles 0.1-0.2 or 0.2-0.3 micron in size.
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