Labconco Fume Adsorbers 3955422 - Manual (Page 20)

Chapter 5: Appropriate Applications for Your Enclosure
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Organics must have time weighted exposure limits (TWA) of 100 PPM or greater.
Chemicals must have a detectable odor at concentrations below the TWA for the
chemical.
Chemicals must be designated by NIOSH guidelines as acceptable for use with
chemical cartridge-type respirators (the exception is formaldehyde and
ammonia/amines, which used impregnated carbon). Chemicals not listed by
NIOSH in the Pocket Guide must be approved by Labconco Product Specialist (or
Engineering).
Inlet concentration must never exceed the IDLH (Immediately Dangerous to Life
and Health) concentrations.
Chemicals having a recommendation by NIOSH of at least “Escape GMFOV”
(Gas Mask Full-Face Respirator).
When evaporating a mixture of chemicals, the chemical having the lowest TWA
will be used to determine if the mixture meets the guidelines.
Call a Labconco Product Specialist at 1-800-821-5525 for assistance in
determining chemical appropriateness.
Definition of Terms
NIOSH – National Institute for Occupational Safety and Health/Mine Safety and
Health Administration. (U.S.A.)
TWA – Recommended Exposure Limits expressed as a Time Weighted Average.
The exposure limit for that chemical for up to a 10-hour workday, 40 hours a
week. Expressed in units of parts per million or milligrams per cubic meter.
Odor Threshold – The value in parts per million or milligrams per cubic meter for
which one might expect to smell a chemical’s presence in the air. This value is very
subjective and detection will vary with the sensitivity of one’s nose. The period of
time until the odor threshold is reached in the exhaust stream can be estimated from
Labconco’s exclusive chemical assessment program. Contact Labconco on
estimates for carbon filter life for specific applications. See Chapter 6.
Saturation Level or Time – There is a limit to the amount of chemical that can be
adsorbed by activated carbon or neutralized by chemically-treated carbon. Once
the capacity of the carbon is reached, it is considered to be saturated and will
adsorb (or neutralize) no further material; the outlet concentration of the chemical
will equal the inlet concentration from that point until the filter is replaced. (Note
that the capacity of activated carbon is not a constant, but varies with the inlet
concentration). Labconco Product Specialists can determine the estimated
saturation time for a particular chemical.