Agriculture Reference
In-Depth Information
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Devices consisting of a body and one or more cartridges that contain
air-purifying materials.
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Devices consisting of a body and a canister that contains air-purifying
materials.
Cartridges
may contain either dust/mist-filtering material or va-
por-removing material. For pesticide handling tasks where vapor removal is
needed, a prefilter must be used with the vapor-removing cartridge. The prefil-
ter removes dusts, mists, and other particles before the air passes through the
vapor-removing cartridge. A few vapor-removing cartridges have an attached
prefilter, but most are sold separately. Separate prefilters are preferred for use
with pesticides, because they often need to be replaced before the va-
por-removing cartridge is used up.
Some cartridge-type respirators are one-piece units with cartridges perma-
nently attached to the facepiece. After use, the entire unit is discarded. Other
cartridge respirators are two-piece units with removable cartridges and a body
that can be cleaned and reused. The dust/mist filtering or vapor-removing car-
tridges and the prefilters can be replaced when they lose their effectiveness.
Figure 6.14
shows a worker using an air-purfying respirator-half mask.
Worker is also wearing goggles with indirect air vents and a large brimmed hat
for protection
A
canister
contains both dust/ mist-filtering and vapor-removing mate-
rial. Canisters contain more air-purifying material than cartridges. They last
much longer and may protect you better in situations where the concentration
of gas or vapor in the air is high. They are also much heavier and more un-
comfortable to wear.
Canister-type respirators are often called gas masks. They usually have
the canister connected directly to the facepiece or worn on a belt and connected
to the facepiece by a flexible hose. The body is designed to be cleaned and
reused. The canisters can be replaced when necessary.
a.
Selecting and Using Dust/Mist Filtering Devices
Dust/mist filtering masks and cartridges are approved by NIOSH and
MSHA. You must wear one that has their stamp of approval. Nonapproved
filters are not as protective and are not acceptable.
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Pesticide handlers must wear dust/mist-filtering masks or cartridges
with NIOSH/MSHA approval number prefix TC21C.
Look for a dust/mist mask that is held in place by two straps. One-strap
styles are not approved by NIOSH and MSHA, because they do not keep the
respirator adequately sealed against the face.
