Agriculture Reference
In-Depth Information
structions on some other materials will tell you to replace them after a spe-
cific number of hours of use. If there are no instructions about replacement,
change the cartridge or canister after about 8 hours of use.
c.
Air-Delivery Systems
Air-purifying respirators draw air through the filters and vapor-removing
materials in one of two ways. Ordinary air-purifying respirators depend on the
wearer's lung power to draw air through the purifying material with each
breath. Powered air-purifying respirators (PAPA's) assist the wearer by pull-
ing the air through mechanically. Dust/mist masks and most cartridge and
canister respirators are nonpowered air-purifying respiators.
If you have a respiratory problem, even a temporary problem such as a
cold or allergy, you cannot wear nonpowered cartridge and canister respirators.
You need strong lung pressure to draw the air through the cartridges into your
lungs. Even persons with normal lung capacity cannot wear these respirators
for long periods of time because they tend to be hot, uncomfortable, and ex-
hausting.
Before these respirators, have a medical examination to make sure that
you do not have a medical condition that would prevent you from using such
devices. If you have trouble breathing while wearing a respirator even though
you have used and cared for it correctly, see your physician to find out whether
you have a health problem.
Powered air-purifying respirators use a blower to draw air to the user.
PAPRs should not be confused with air-supplying respirators, because they do
not supply clean air. The air is cleaned by cartridges or canisters, as it is with
other air-purifying respirators. These respirators are available as lightweight
backpacks, or they may be mounted on or in application equipment where the
power is supplied by the vehicle's electrical systems.
d.
Fitting Air-Purifying Respirators
Respirators fit wearers in one of two ways. Most must seal tightly to the
face; others are loose-fitting.
Face-seali ng respi rators
must form a tight seal again st your face to
be effective. Otherwise, pesticides can leak in around the edges. People with
beards cannot wear this style of respirator, because a tight seal cannot be
formed through the hair. These respirators must be fitted to each wearer and
are not interchangeable among handlers.
Dust/mist masks are face-sealing respirators. They fit over your nose and
mouth and have a clip that you press around the bridge of your nose to help
