Labconco Fume Adsorbers 3955422 - Manual (Page 23)

Chapter 6: Maintaining Your Enclosure
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recommendation is formaldehyde or any carcinogen or suspected
carcinogen. These hazardous chemicals must be checked at least every 10%
of the total estimated time. Gas detector tubes for the specific chemicals
that are being used in the enclosure can be obtained from your laboratory
supply dealer.

Replace carbon filters when chemical breakthrough is indicated by odor,
time, detector tube, or for some chemicals, analytical instrumentation. See
“Replacing Carbon Filters” section of this manual in Chapter 6.
Determination of When to Replace
Carbon Filters and How to Replace
Carbon filter(s) MUST be replaced when any one of the following two conditions
are met:
1. The filtered enclosure outlet (exhaust) concentration approaches the inlet
concentration, indicating filter saturation.
2. The odor in the work area becomes intolerable or the concentration of the
chemical in the work area is greater than the TWA.
Catalog # Filter
Size Pounds of
Carbon Carbon Type For use with Adsorption
weight Adsorption
Volume
6961300 9x26x1.38 6.0 Organic
Vapor Organic
Vapors Varies, see
chemical
chart Varies, see
chemical guide and
chapter 6
6961301 9x26x1.38 7.5 Impregnated
Formasorb Formaldehyde 10%, 0.75lbs 851 ml of 37%
Formalin
6961302 9x26x1.38 8.8 Impregnated
Ammonasorb Ammonia and
Amines 10%, 0.88lbs 800 ml of 37%
Formalin
There are four means of determining when its time to change the carbon filters (not
shown in the order of preference).
Odor - A person’s sensitivity to odor, tolerance of odor and their comfort level
under odoriferous conditions vary with the individual. While odor is an indicator
that chemicals are passing through the carbon filter, several points need to be
understood:

Odor within the room is not necessarily an indication of saturation or
hazardous exposure concentrations.

Odor can be used as a prompt to sample the chemical concentration on the exit
side of the carbon filter.

Organic chemicals approved for use in the filtered enclosure have odors that
are detectable before reaching the time weighted exposure limits.