Agriculture Reference
In-Depth Information
form a seal. Most cartridge and canister respirators are also face-sealing respi-
rators. Full-face styles form and keep a tight seal better than half-face styles.
Many pesticide handlers are not adequately protected while wearing
face-sealing cartridge and canister respirators, because they often break the seal
by pulling the respirator away from their face to get temporary relief from the
heat, sweat, itching, or difficult breathing. Once the seal is broken in the ex-
posure area, the respirator's ability to protect you is greatly reduced.
Face-sealing cartridge and canister respirators are most useful for short-term
tasks.
Your face-sealing respirator should be tested before you wear it in a situa-
tion where you may inhale pesticides. There are two types of fit tests: qualita-
tive and quantitative.
They ensure that the respirator is operating correctly and
that you are being protected.
Have a
fit test
before using your cartridge or canister respirator the first
time, and then be retested periodically. Get the fit test through a program ap-
proved by NIOSH and OSHA, the agencies that regulate respirator fit testing.
The Cooperative Extension Service in your locality may be able to tell you
where to find an approved fit testing program.
Figure 6.16
shows a qualita-
tive fit test.
The two main types of fit tests are:
•
qualitative testing—whether the wearer can detect a test substance by
irritation, odor, or taste
•
quantitative testing—measuring the actual amount of a test substance
that gets inside the facepiece.
A
fit check
is an on-the-spot check that you should do to make sure the
respirator is still working correctly. Do a fit check each time you wear a
face-sealing respirator.
There are two methods for checking the seal of the facepiece against your
face. To check by the first method:
•
close off the inlet of the canister or cartridge (cover it with your
palm, replace the caps, or squeeze the breathing tube so that it does
not allow air to pass)
•
Inhale gently so that the facepiece collapses slightly
•
Hold your breath for about 10 seconds.
If the facepiece remains slightly collapsed and no inward leakage is de-
tected, the respirator probably fits tightly enough and will work correctly.
This method does not work for dust/mist masks.
