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THE ORCBS > Occupational Safety > Programs & Guidelines > Respiratory Protection > Respiratory Protection Program >
 RESPIRATORY
PROTECTIVE EQUIPMENT
The basic purpose
of any respirator is to protect the respiratory system from inhalation
of hazardous atmospheres. Respirators provide protection either
by removing contaminants from the air before it is inhaled or by
supplying an independent source of respirable air. See Table
1 and Table 2 for more detailed information
on respirator capabilities and modes of operation.
A. Air-Purifying
Respirators
Ambient air,
prior to being inhaled, is passed through a filter, cartridge, or
canister, which removes contaminants. Different filters are required
to remove different contaminants.
1. Non-powered
Air-Purifying Respirator
The breathing
action of the wearer operates the non-powered type of respirator.
Equipped with a tight-fitting facepiece and filter(s), the respirator
is secured to the face by means of a strap or harness. The wearer
pulls air through the filters during inhalation. Oxygen must
be present in sufficient levels (see Table
1) when using an air-purifying respirator.
a) The Filtering
Facepiece
These types
of respirators have a facepiece that is composed mostly of the
filter. They do not provide as high of a level of protection
as a half-mask respirator.
i. N95
respirators
These
respirators are used on campus for protection against biohazardous
aerosols. They do not filter any organic vapors, acid gases
or provide adequate protection against particulates. N95 respirators
have a NIOSH approval number starting with TC-84xxx (xxx will
be a specific number for each NIOSH approval), and are available
with or without an exhalation valve. N95 respirators must
be fit tested in a required use situation, and should be disposed
of after each use.
ii. Dust
Masks (picture 1),
Dust masks,
which are generally used for nuisance dust such as cement
and hay dusts are also filtering facepieces. They do not filter
any organic vapors, acid gases or provide adequate protection
against particulates. This type of respirator does not have
a NIOSH approval number, and can not be fit tested. They should
not be used as a substitute for an N95, or for any tight fitting
half or fullface respirator. These respirators should be discarded
when resistance to breathing becomes excessive, or after each
use.
b) The half-mask
(picture 2) and full facepiece (picture 3) respirators provide
greater protection than the dust mask because their construction
allows for a better fit. These respirators provide protection
against dusts, mists, fumes, vapors, gases, or any combination
of these contaminants depending on the type of filter used.
The full facepiece provides that greatest degree of protection
in the APR class, and protects the eyes as well.
2. Powered
Air-Purifying Respirator (PAPR)
The powered
type contains a portable blower, which pushes ambient air through
a filter and then supplies purified air to the wearer. The powered
type is equipped with a tight-fitting facepiece or a loose-fitting
helmet, hood, or suit. A loose fitting PAPR does not require a
fit test. However, inspection to insure proper flow rate and operation
is required for safe use.
B.
Atmosphere-Supplying Respirators
Atmosphere
supplying respirators provide a clean source of air from a tank
or compressor to the wearer. Atmosphere-supplying respirators provide
a greater level of protection than air-purifying respirators because
they don't rely on a filtering mechanism to provide clean air.
a)
Self-Contained Breathing Apparatus (SCBA)
The
wearer carries a supply of air, oxygen, or oxygen-generating material.
Normally equipped with full facepiece, but may be equipped with
a half-mask facepiece, helmet, hood. See picture 4.
b)
Air-Line Respirator
Respirable
air is supplied through a small-diameter hose from a compressor
or compressed air cylinder. The hose is attached to the wearer
by a belt and can be detached rapidly in an emergency. A flow-control
valve or orifice is provided to govern the rate of airflow to
the wearer. Exhaled air passes to the ambient atmosphere through
a valve or opening in the enclosure (facepiece, helmet, hood,
or suit).
c)
Breathing Air Quality
Compressed
air and liquid air shall be of high purity. Breathing air shall
meet at least the requirements of the specification for grade
D breathing air described in Compressed Gas Association Commodity
Specification G-7.1-1966. A compressor used to supply breathing
air shall be a breathing air-type compressor. Compressors shall
be constructed and situated so as to avoid entry of contaminated
air into the system and suitable in-line purifying sorbent beds
and filters installed to further assure breathing air quality.
Never hook an air-line respirator up to an oxygen tank.
Medical
Certification
Respiratory Protection Program
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