Labconco Class I Enclosure Models 3980423 - Manual (Page 35)

Chapter 5: Appropriate Applications for Your Filtered Enclosure
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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 Technical specialists can determine with the
computerized carbon-modeling program the estimated time saturation for a
particular chemical. When using a HEPA filter alone in all filtered enclosures or
in combination with an Odor Control carbon filter, the speed control will need to
be increased to allow for HEPA filter loading. Measure filtered enclosure face
velocity with an anemometer.
IDLH (Immediately Dangerous to Life and Health) – An atmosphere that poses
an immediate hazard to life or produces immediate irreversible health effects.
IDLH concentrations should not be approached in the enclosure.
Appropriate Chemicals for Odor Control
Carbon Filters
Below is a general set of rules to determine appropriateness of chemical usage.
Selected organic chemicals considered to be occupational
carcinogens by NIOSH can be used in the filtered enclosure
with carbon filters under rigid restrictions. See separate
discussion on carcinogens for special instructions.
Organics must have time weighted exposure limits (TWA) of 1 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 chemical
appropriateness.
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