following definitions are important terms used in the respiratory protection standard in this section.
Air-purifying respirator means a respirator with an
air-purifying filter, cartridge, or canister that removes specific air contaminants by passing ambient air through
the air-purifying element.
Assigned protection factor
(APF) means 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 as specified by this section.
Atmosphere-supplying respirator means a respirator that
supplies the respirator 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 means a container with a filter,
sorbent, or catalyst, or combination of these items, which removes specific contaminants from the air passed through
Demand respirator means
an atmosphere-supplying respirator that admits breathing air to the facepiece only when a negative pressure is
created inside the facepiece by inhalation.
Emergency situation means
any occurrence such as, but not limited to, equipment failure, rupture of containers, or failure of control
equipment that may or does result in an uncontrolled significant release of an airborne contaminant.
Employee exposure means exposure to a concentration of an
airborne contaminant that would occur if the employee were not using respiratory protection.
End-of-service-life indicator (ESLI) means a system that
warns the respirator user of the approach of the end of adequate respiratory protection, for example, that the
sorbent is approaching saturation or is no longer effective.
Escape-only respirator means a respirator intended to be
used only for emergency exit.
Filter or air purifying
element means a component used in respirators to remove solid or liquid aerosols from the
Filtering facepiece (dust
mask) means 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 means a quantitative estimate of the fit of a
particular respirator to a specific individual, and typically estimates the ratio of the concentration of a
substance in ambient air to its concentration inside the respirator when worn.
Fit test means 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.)
a rigid respiratory inlet covering that also provides head protection against impact and penetration.
High efficiency particulate air (HEPA) filter means a filter
that is at least 99.97% efficient in removing monodisperse particles of 0.3 micrometers in diameter. The equivalent
NIOSH 42 CFR 84 particulate filters are the N100, R100, and P100 filters.
Hood means a respiratory inlet covering that completely
covers the head and neck and may also cover portions of the shoulders and torso.
Immediately dangerous to life or health (IDLH) means an
atmosphere that poses an immediate threat to life, would cause irreversible adverse health effects, or would impair
an individual's ability to escape from a dangerous atmosphere.
Interior structural firefighting means the physical activity
of fire suppression, rescue or both, inside of buildings or enclosed structures which are involved in a fire
situation beyond the incipient stage. (See 29 CFR 1910.155)
Loose-fitting facepiece means a respiratory inlet covering
that is designed to form a partial seal with the face.
Maximum use concentration (MUC) means the maximum
atmospheric concentration of a hazardous substance from which an employee can be expected to be protected when
wearing a respirator, and is determined by the assigned protection factor of the respirator or class of respirators
and the exposure limit of the hazardous substance. The MUC can be determined mathematically by multiplying the
assigned protection factor specified for a respirator by the required OSHA permissible exposure limit, short-term
exposure limit, or ceiling limit. When no OSHA exposure limit is available for a hazardous substance, an employer
must determine an MUC on the basis of relevant available information and informed professional judgment.
Negative pressure respirator (tight fitting) means a
respirator in which the air pressure inside the facepiece is negative during inhalation with respect to the ambient
air pressure outside the respirator.
Oxygen deficient atmosphere means
an atmosphere with an oxygen content below 19.5% by volume.
Physician or other licensed health care professional (PLHCP) means
an individual whose legally permitted scope of practice (i.e., license, registration, or certification) allows him
or her to independently provide, or be delegated the responsibility to provide, some or all of the health care
services required by paragraph (e) of this section.
Positive pressure respirator means a respirator in which the
pressure inside the respiratory inlet covering exceeds the ambient air pressure outside the respirator.
Powered air-purifying respirator (PAPR) means an
air-purifying respirator that uses a blower to force the ambient air through air-purifying elements to the inlet
Pressure demand respirator means
a positive pressure atmosphere-supplying respirator that admits breathing air to the facepiece when the positive
pressure is reduced inside the facepiece by inhalation.
Qualitative fit test (QLFT) means a pass/fail fit test to
assess the adequacy of respirator fit that relies on the individual's response to the test agent.
Quantitative fit test (QNFT) means an assessment of the
adequacy of respirator fit by numerically measuring the amount of leakage into the respirator.
Respiratory inlet covering means that portion of a
respirator that forms the protective barrier between the user's respiratory tract and an air-purifying device or
breathing air source, or both. It may be a facepiece, helmet, hood, suit, or a mouthpiece respirator with nose
apparatus (SCBA) means an atmosphere-supplying respirator for which the breathing air source is
designed to be carried by the user.
Service life means
the period of time that a respirator, filter or sorbent, or other respiratory equipment provides adequate protection
to the wearer.
(SAR) or airline respirator means an atmosphere-supplying respirator for which the source of
breathing air is not designed to be carried by the user.
This section means this respiratory protection standard.
Tight-fitting facepiece means a respiratory inlet covering
that forms a complete seal with the face.
User seal check means
an action conducted by the respirator user to determine if the respirator is properly seated to the face.