OHD Quantifit2, Руководство пользователя

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Chapter 25 | Appendix C: Terminology |
25
Appendix C: Terminology
Air-purifying respirator (APR) a respirator with
a filter, cartridge, or canister that removes
specific air contaminants by passing ambient air
through a purifying element.
Assigned protection factor (APF) a numerical
indicator of the level of protection a respirator
can be expected to provide when it is worn
correctly and functioning properly. It represents
the workplace level of respiratory protection that
a respirator or class of respirators is expected to
provide to employees when the employer
implements a continuing, effective respiratory
protection program.
Example: An APF of 10 means that no more
than one-tenth of the contaminants to which
the worker is exposed will leak into the inside
of the respirator and it can be safely used in an
atmosphere that has a hazardous
concentration of up to 10 times the Permissible
Exposure Limit (PEL) or other exposure limit for
that hazard.
Atmosphere-supplying respirator a respirator
that supplies the user with breathing air from a
source independent of the ambient atmosphere
and includes supplied-air respirators (SARs) and
self-contained breathing apparatus (SCBA) units.
Canister or cartridge a container with a filter,
sorbent, catalyst, or combination of these items,
which removes specific contaminants from the air
passed through the container.
Condensation Nuclei Counting (CNC ) method
of Quantitative fit testing (QNFT) also known as
ambient aerosol which measures aerosol
concentration inside the breathing zone of a
respirator with the use of a probe and outside of
the respirator. The aerosols measured inside the
respirator are assumed to be the result of
leakage.
Controlled Negative Pressure (CNP) method of
Quantitative fit testing (QNFT) that pulls and
maintains a negative pressure inside a respirator
by removing, and directly measuring, any air that
leaks into the facepiece.
Escape-only respirator a respirator intended to
be used only for emergency exit.
Filter or air purifying element a component
used in respirators to remove solid or liquid
aerosols from the inspired air.
Filtering facepiece (dust respirator) a negative
pressure particulate respirator with a filter as an
integral part of the facepiece or with the entire
facepiece composed of the filtering medium.
Fit factor a numerical representation of the fit of
a respirator to a specific individual; typically
estimating the ratio of the concentration of a
substance in ambient air to its concentration
inside the respirator when worn.
Example: Controlled Negative Pressure
converts the leak rate it has measured into a fit
factor. To do this it takes the modeled
breathing rate and divides it by the measured
leak rate. This is how you get each individual
exercise’s fit factor. Another way to look at this
is that it is the ratio of the total air inhaled to
the possibly contaminated air inhaled.
Fit test the use of a protocol to qualitatively or
quantitatively evaluate the fit of a respirator on
an individual. (See also Qualitative fit test QLFT
and Quantitative fit test QNFT.)
Helmet a rigid respiratory inlet covering that
also provides head protection against impact and
penetration.
High efficiency particulate air (HEPA) filter a
filter that is at least 99.97% efficient in removing
monodisperse particles 0.3 micrometers (µ m) in
diameter. The filtration efficiency increases for
particle diameters both less than and greater
than 0.3 µ m. The equivalent NIOSH 42 CFR 84
particulate filters are the N100, R100, and P100
filters.
Hood a respiratory inlet covering that completely
covers the head and neck and may also cover
portions of the shoulders and torso.