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Compressed Breathing Air, Page 1
Compressed Breathing Air
1. Introduction
a. Atmosphere supplying respirators, including self-contained breathing apparatus (SCBA)
and supplied-air (airline) respirators are the most complex types of respirators and require
detailed respirator programs to support their use. One of most important elements of
these respirator programs are procedures to ensure atmosphere supplying respirators
provide high quality breathing air to the wearer.
b. There are several standards, regulations and instructions discussed in Section 2 that
establish breathing air quality requirements and govern the use of atmosphere-supplying
respirators.
2. Breathing Air Quality Standards
a. 29 CFR 1910.134
(1) The Occupational Safety and Health Administration’s Respiratory Protection Standard,
Reference 1, requires procedures to ensure adequate quality, quantity and flow of
breathing air for atmosphere-supplying respirators. Reference 1 requires compressed
and liquid oxygen shall meet the United States Pharmacopoeia requirements for
medical or breathing oxygen. Also, compressed breathing air shall meet at least the
requirements for Grade D breathing air described in Reference 2. OSHA specifically
states that the requirements for Grade D breathing air according to Reference 2 are an
oxygen content (v/v) of 19.5-23.5%, a hydrocarbon (condensed) content of 5
milligrams per cubic meter of air or less, a carbon monoxide (CO) content of 10 parts
per million (ppm) or less, a carbon dioxide content of 1,000 ppm or less, and a lack of
noticeable odor. Per Reference 1, compressors used to supply breathing air to
respirators must be constructed and situated to minimize moisture content so that the
dew point at 1 atmosphere pressure is 10°F below the ambient temperature.
(2) Per Reference 1, cylinders of purchased breathing air are required to have a certificate
of analysis from the supplier stating that the breathing air meets the requirements for
Grade D breathing air. The moisture content in the cylinder cannot exceed a dew point
of -50°F (-45.6°C) at 1 atmosphere pressure.
(3) Reference 1 also contains requirements for compressors used to supply breathing air.
These requirements are detailed below.
b. OPNAVINST 5100.23 Series, Navy Safety and Occupational Health Program Manual
(1) Reference 4 states breathing air must at least meet the minimum Grade D breathing
air requirements of Reference 1, which are established by Reference 3. Reference 4
states that breathing air must be monitored quarterly and the results retained in the
safety office for five years.
(a) A NOTE contained in Reference 4 states, "Monitoring does not apply to ambient air
breathing apparatus.” Ambient Air Breathing Apparatuses (AABAs) are exempt
from the quarterly breathing air testing requirement.
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(b) AABAs are defined as portable electrically or pneumatically-powered oil-less air
pumps which supply breathing air to low pressure continuous flow respirators.
Although AABAs do not generate oil mist, oil vapor or carbon monoxide, they also
do not produce Grade D breathing air. The ambient air that is drawn through the
inlet particulate filter is delivered to the respirator(s) without significant change to
the air quality. Therefore, air inlets must be placed in contaminant-free
environments.
(2) Reference 4 requires newly purchased compressors (except AABA) to be equipped with
continuous carbon monoxide monitor and alarm systems. Existing compressors must
have continuous carbon monoxide monitor and alarm systems installed when they are
upgraded during major overhaul maintenance. This paragraph also requires that
carbon monoxide monitor and alarm systems be calibrated according to
manufacturers’ instructions. More information on this issue is provided in Section 4,
Standard Specific Compressor Requirements, below.
c. OPNAVINST 5100.19 Series, Navy Safety and Occupational Health Program Manual for
Forces Afloat
(1) Reference 5 requires testing breathing air compressors quarterly to ensure Grade D air
quality is met. Like Reference 4, there are carbon monoxide monitor and alarm
requirements, which are discussed in Section 6 below.
(a) Ship's low pressure air is not suitable for use as breathing air unless specifically
tested and certified to meet Grade D air criteria.
(b) AABA air quality testing is not required.
d. CGA G-7.1, Commodity Specification for Air
(1) The Compressed Gas Association, Inc. (CGA) published the seventh edition of CGA G-
7.1 in 2018. American National Standards Institute (ANSI) jointly published the first
three editions (1966, 1973, and 1989) of this standard as ANSI Z86.1. However, the
2011, 2004 and the 1997 editions were published solely by CGA.
(a) CGA G-7.1-1989 edition changes from 1973 edition:
1. Grades B, C, F and H gaseous air were discontinued because they no longer had
major usage in industry.
2. Type II - Grade B liquid air was discontinued.
3. Established four new gaseous air classes - K, L, M and N.
4. Reduced the maximum allowable concentration of carbon monoxide in Grade D
air from 20 ppm to 10 ppm.
(b) The CGA G-7.1-1997 standard discontinued three quality verification levels
(Grades) from the 1989 edition, which included Grades K, G and M. OSHA was not
aware of the 1997 edition of CGA G-7.1 when they promulgated their final
Respirator Standard, 29 CFR 1910.134 on 8 January, 1998. The respirator standard
(Reference 1) required compressed breathing air to meet at least the requirements
for “Type I - Grade D” breathing air described in CGA G-7.1- 1989. However, the
Type I and II terminology for breathing air was discontinued after the 1989 edition
of CGA G-7.1. OSHA corrected this error to specify “Grade D” instead of “Type I -
Grade D” in the 23 April 1998 Federal Register.
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(c) To prevent self-contained breathing apparatus (SCBA) valves from freezing, the
1997 and 2004 versions of CGA G-7.1 specified Grade L air for use with SCBA worn
in extreme cold because of the Grade L air low moisture requirements of 24 ppm
and -65° F dew point. However, the only other requirement for Grade L air was
19.5% to 23.5% oxygen content. Although the low moisture requirement made
sense, it did not make sense for Grade L air to not require the same limiting
characteristic requirements of Grade D air. This was corrected in the 2011 version
of CGA G-7.1, in which Grade L and Grade D have the same limiting characteristics,
except for the more stringent moisture requirements of Grade L air for use in SCBA
worn in extreme cold. Table 2 of Reference 3 defines the typical, but not all
inclusive, industrial uses for CGA grades of air. These uses are listed in Table 1.
Table 1-Grades of Compressed Air
(d) See Reference 3, Table 1 for maximum concentrations of the air constituents for
each grade of compressed air. A blank box in the table indicates no maximum
limiting characteristic. This does not mean that the substance is not present, but
indicates that testing that component is not a requirement for compliance with the
specification.
3. Grade D Air Limiting Characteristics
a. Oxygen - 19.5% to 23.5%
(1) Reference 1 does not allow the use of compressed oxygen in atmosphere-supplying
respirators that have previously used compressed air. This is to prevent a flammability
hazard from high pressure oxygen coming in contact with any oil introduced inside the
airline hoses from compressed air operations. Reference 1 further requires that oxygen
concentrations greater than 23.5% are used only in equipment designed for oxygen
service or distribution (e.g., closed circuit respirators).
(2) It may seem counterintuitive that oxygen content in compressed breathing air even
need be sampled because air intakes located outdoors should contain 20.9% oxygen
since that is its concentration in ambient, atmospheric air. Unfortunately, there is no
guarantee that every employer will place air intakes in proper locations or properly
maintain their air compressors.
(3) Although air intakes are required to be properly located in fresh outdoor atmospheres
such as above roof level and away from ventilation exhausts, they are sometimes
improperly located outdoors on loading docks and exposed to vehicle exhaust.
Depending on the circumstances, there could also be a chance of oxygen depletion by
the presence of other substances where air intakes are improperly located. Oxygen can
CGA Grade
Industrial Uses
A
Industrial compressed air
L
Self-Contained Breathing Apparatus (SCBA) air
D
OSHA breathing air
E
Self-contained underwater breathing apparatus (SCUBA)
J
Specialty grade air, analytical applications
N
Medical air USP, food applications
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also be consumed inside of oil-lubricated compressors running hot in the presence of
hydrocarbons.
(4) Other factors that influence the oxygen concentration include moisture in the air and
altitude. Moisture is the most variable component of the atmosphere. Water vapor in
the atmosphere can range from 0% to 4%. In dry air (0% water vapor), the oxygen
concentration is approximately 20.9%; however, atmospheres with 4% water vapor
contain only 20.06% oxygen.
(5) At higher altitudes the percentage of oxygen remains the same as at sea level but the
partial pressure of oxygen decreases, which effectively lowers the oxygen
concentration available for respiration.
(a) Altitude affects the concentration of oxygen both in ambient air and in
compressed breathing air. OSHA states in Reference 1 that all oxygen-deficient
atmospheres (less than 19.5% O
2
by volume) shall be considered immediately
dangerous to life or health (IDLH) and that personnel entering these atmospheres
must wear either SCBA or combination airline/SCBA.
(b) There is an exception when the employer can demonstrate that under all
foreseeable conditions, the oxygen concentration can be maintained within the
ranges at the altitudes specified in Table II of the OSHA Respirator Standard
(reproduced below). If so, then any atmosphere supplying respirator, including
airline respirators may be used.
Table 2
Altitude (ft.)
Oxygen deficient Atmospheres (% 02) for which the
employer may rely on any atmosphere-supplying
respirator
Less than 3,001
3,001-4,000
4,001-5,000
5,001-6,000
6,001-7,000
7,001-8,000
16.0-19.5
16.4-19.5
17.1-19.5
17.8-19.5
18.5-19.5
19.3-19.5
(c) At high altitudes, References 1 and 6 require oxygen-enriched breathing air for
atmosphere-supplying respirators.
(d) Per Reference 1, OSHA allows acclimated workers to perform their work without
atmosphere-supplying or oxygen-supplying respirators, at altitudes up to 14,000
feet altitude, as long as the ambient oxygen content remains above 19.5%.
b. Carbon monoxide (CO) - 10 ppm
(1) CGA G-7.1 -1973 listed the maximum limit for CO as 20 ppm. The limit for CO was
changed in 1989 to 10 ppm. CO is the deadliest of the toxic gases commonly found in
compressed air. Because CO is colorless and odorless, it is impossible for respirator
wearers to detect. CO combines readily with hemoglobin in red blood cells and
prevents the transfer of oxygen to the tissues, causing oxygen starvation or hypoxia.
(2) Possible sources of CO include:
(a) Motor exhaust drawn into compressor air intake.
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(b) Generated within compressors as combustion product of fuels, lubricants and
overheated oils.
(c) Generated within compressors from oxidation of overheated sorbent filters. CO
accumulated on a filter can be released when there is a drop in operating pressure.
c. Oil - 5 mg/m
3
at normal temperature and pressure (NTP)
(1) Oil was formerly called condensed hydrocarbons in the 1973 edition of CGA G-7.1.
Large particles of condensed hydrocarbons or oil, can be removed by the body's
clearance mechanisms (i.e., phagocytosis and mucociliary escalator). Smaller oil
particles are retained and may be hazardous depending on the type and amount. Oil
mist deposits in the alveoli can cause an intense inflammation, known as lipoid
pneumonia.
(2) Oil mist can also cause emphysema by dilating and rupturing the alveoli, thus
decreasing the total surface area available for the transfer of oxygen and carbon
dioxide. Possible oil sources include dust and pollen, motor exhaust pulled into the
compressor air intake, and oil generated inside the compressor if lubricants escape
through faulty piston rings.
d. Carbon dioxide (CO
2
) - maximum 1000 ppm.
(1) Carbon dioxide stimulates the respiratory center. A buildup of CO
2
in breathing air
increases the breathing rate, which can deplete SCBA air supply more rapidly and
increase inhalation of other contaminants.
(2) High CO
2
levels can be indicative of compressor problems. Carbon monoxide is
converted to CO
2
by hopcalite in the compressor CO filter. Therefore, high
concentrations of CO
2
can result from the hopcalite catalyzing elevated concentrations
of CO. Grade E air for SCUBA air was revised in the 1989 edition increasing the
maximum allowable level for carbon dioxide from 500 ppm to 1,000 ppm.
e. Odor - Grade D air should have no pronounced odor. Odor is a subjective measurement.
f. Water
(1) The lower the dew point, the lower the moisture content. If the ambient temperature
falls below the dew point of compressed breathing air, any moisture present can
condense and form liquid water. If the ambient temperature is freezing, then regulator
and control valves can freeze. Adiabatic cooling further contributes to the problem of
freezing. Adiabatic cooling occurs in atmosphere-supplying respirators as high pressure
compressed air loses heat when its pressure is reduced. According to Reference 6,
when ambient temperature, high pressure air (2000 to 4000 pounds per square inch
[psi] and about 70°- 85°F) is reduced by the regulator to 80 to 100 psi for airline
respirator use the air temperature drops 25° to 40°F or more.
(2) Moisture content or dew point is expressed in ppm and °F at one atmosphere. Per
OSHA, Reference 1, the dew point of compressed breathing air at one atmosphere
must be 10° F below the ambient temperature. Reference 1 also requires that the
moisture content in cylinders of breathing air purchased from suppliers does not
exceed a dew point of -50°F (-45.6°C) at one atmosphere pressure.
(3) Several respirator documents detail moisture content in breathing air.
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(a) Note 7 from Table 1 of Reference 2 states that water content varies with intended
use. SCBA breathing air must not have a dew point temperature exceeding -65°F
(which corresponds to a moisture content of 24 ppm v/v) or the dew point
temperature of the breathing air at one atmosphere must be 10°F lower than the
coldest temperature expected in the atmosphere where the respirator will be
worn. Water vapor will vary depending on relative humidity and dew point.
Basically, there should be no liquid water in the breathing air to prevent freezing in
atmosphere-supplying respirators. Table 3 of Reference 2 provides dew point
temperatures ranging from -130°
F to 0°
F. This table covers the temperature range
most likely found in the workplace where adiabatic cooling produced by SCBA and
airline respirators could cause freezing. Moisture measurements taken during
compressed breathing air quality testing can be compared to these table values to
convert between dew point and moisture content.
(b) Table 3 of Reference 2 lists atmospheric dew point temperatures and their
corresponding moisture contents; however, the “pressure dew point temperature”
of compressed breathing air becomes a critical factor in evaluating air quality of
breathing air use in extremely cold temperatures, such as occur in some geographic
locations, such as in Canada and Alaska. The increased pressure of breathing air for
atmosphere supplying respirator results in the “pressure dew point temperature”
of the compressed air being considerably lower than the dew point of ambient air
(at one atmosphere of pressure) with the same temperature.
(c) Per Reference 7, the dew point of breathing air used with airline respirators shall
have a maximum dew point 10°F lower than the lowest ambient temperature to
which any regulator or control valve on the respirator or air supply system may be
exposed. Reference 7 also provides Table A.9-2 for use in determining the
maximum water content for the pressure of the airline respirator system for the
lowest temperature in which the airline respirator will be used.
(d) Table A.9-2 of Reference 7 takes into account pressure dew point temperatures at
typical operating pressures of airline respirators and is used for determining the
allowable moisture content to protect against valve freezing. To use Table A.9-2 of
Reference 7, locate the operating pressure for the airline respirator and find the
lowest temperature in which the respirator will be used, then read the maximum
water content from the left column.
(e) Table A.9-3 of Reference 7 takes into account pressure dew point temperatures at
typical operating pressures of SCBA and is used for determining the allowable
moisture content to protect against valve freezing. To use Table A.9-4 of Reference
7, locate the operating pressure of the SCBA and find the lowest temperature in
which the respirator will be used, then read the maximum water content from the
left column.
(4) Other Contaminants - There are no limits for other contaminants (total hydrocarbon,
nitrogen dioxide, nitric acid, sulfur dioxide, etc.) listed in Table 1 of Reference 3 for
Grade D air. However, these should be tested if there is any reason to suspect a
problem.
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4. Testing Breathing Air
a. Per Reference 4, the Navy requires analyzing breathing air quality quarterly to ensure it
meets Grade D criteria. A pressure reducer must be placed in line before the air is
sampled. Test procedures are given in sections 5 and 6 of Reference 3, however, per
Reference 8, “OSHA does not require the use of specific instrumentation to verify the
compliance of air quality requirements prescribed in Compressed Gas Association
Commodity Specification for Air, CGA G-7.1. Any measuring instrument which has an
accuracy of ±25% at a 95% confidence limit is acceptable.”
(1) Oxygen - Paramagnetic-type analyzer, electrochemical-type analyzer, thermal
conductivity-type analyzer, volumetric gas analysis apparatus or a gas chromatograph.
For more details, see section 6.2 of Reference 3.
(2) Water - Electrolytic hygrometer, dew point analyzer, metal oxide capacitor equipped
analyzer, detector tube filled with a color-reactive material, infrared, tuneable diode
laser or cavity ring down spectrometer or a piezoelectric oscillating quartz crystal
hygrometer. For more details, see section 6.3 of Reference 3.
(a) Permanent dew point meters can be installed on sources of compressed breathing
air to continuously monitor moisture content.
(b) These measurements can be used for quarterly air quality testing. Follow all
manufacturer’s instructions. Condensed oil - collect on glass-fiber filter and analyze
gravimetrically, measure using a detector tube containing a color-reactive chemical
for oil only, using a stainless steel mirror for inverted full cylinders, or a visual
inspection of compressor oil and moisture removal systems using a stainless steel
mirror or alternate wiping medium. For more details, see section 6.4 of Reference
3.
(3) Odor - sniff a moderate flow of air from the container being tested. Do not place your
face directly in front of the valve. Cup your hand and waft a sample up to your nose.
For more information, see section 6.5 of Reference 3.
(4) Carbon monoxide and carbon dioxide - gas cell equipped infrared analyzer, detector
tube filled with a color-reactive material, catalytic methanator gas chromatograph or a
gas chromatograph. An electorchemical fuel cell analyzer specific for carbon monoxide
may also be used for carbon monoxide. For more information, see section 6.6 and 6.7
of Reference 3.
(a) Permanent CO meters and alarms can be installed on sources of compressed
breathing air to continuously monitor CO concentration.
(b) These measurements may be used for quarterly air quality testing if the apparatus
is maintained and calibrated per manufacturer’s instructions.
1. Compressors equipped with color-change CO and moisture indicators do not
meet the OSHA requirements for CO alarms. Reference 9 states the following
about CO indicators:
The color change in color-change indicators which detect the presence of CO in
breathing air is a warning of the presence of moisture in the breathing air that
is trapped in the filter. Moisture can render the filter ineffective. Thus, the color-
change indicator cannot be used to detect the presence of carbon monoxide.
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b. Commercially available air test kits may also be used. Air quality testing can also be
contracted.
c. Locations to Test Breathing Air Sources.
(1) Quarterly air quality samples should be taken at specified locations in the distribution
system that are representative of the whole system.
(2) When specifying sample locations, consideration must be given to the parts of the air
distribution system with dead legs and low volume usage. Therefore, collect samples at
risers that have a potential for use.
(3) When a breathing air station is required to be connected to the raiser, first blow out
the pipes in the air distribution system at the riser to ensure that:
(a) all valves leading to the riser are open;
(b) there is sufficient air volume;
(c) sediment in the air distribution lines is removed.
After the system blow down, connect breathing air distribution lines and portable
filtration boxes for supplied air respirators.
5. Compressor Requirements
a. Oil-Lubricated Compressors - Reciprocating compressors (piston compressors) are the
workhorses of the workplace. Most are oil-lubricated to extend service life. When oil is in
the crankcase, it will predictably be discharged into the compression chamber.
Compressors are either oil-lubricated or non-oil-lubricated. Most non-oil-lubricated
compressors use Teflon® parts.
b. Oil-Less Compressors - Oil-less is another name for non-oil-lubricated compressors
because they have no oil in the crankcase. Oil-less reciprocating compressors use sealed
bearings and the piston rings are made from self-lubricating Teflon®. The Teflon® rings seal
the cylinder bore and reduce friction. To further reduce heat, “force-compensated piston
ring” design is used in which the Teflon® rings ride on a cushion of air, sealing during
compression stroke and releasing during intake stroke, which reduces friction and pressure
forces on the rings. Teflon® thermally decomposes at 752° F. However, compressor
manufacturers set their high temperature alarms to shut off the compressors well before
this temperature is ever reached. Particles of Teflon® (median size 1.1 micron) will be
produced especially during the early use of new compressors, but these are filtered out by
the mechanical filtration system required on the compressors. Residual heat from
compression and friction is removed by forced-air cooling, usually by a blower wheel
mounted on the end of the motor shaft directing air over the pistons, cylinders and
bearings to cool them. Oil-less piston air compressors are available with 1/12 to 15
horsepower and with pressure rating up to 220 psi.
(1) Other oil-less compressors include carbon vane compressors and diaphragm
compressors, which are limited to maximum operating pressures of 15 psi and 100 psi,
respectively. Carbon vanes are self-lubricating on cast iron in the presence of humidity
in the atmosphere.
(2) Diaphragm compressors are oil-less because the diaphragm completely isolates the
crankcase from the compression chamber.
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c. Oil-Free Compressors - The term oil-free compressor is misleading. These compressors
actually have oil in the crankcase but are sealed such that oil cannot contaminate the
compression chamber until the seals eventually wear or break.
6. Standard Specific Compressor Requirements
a. Per OSHA in Reference 1, compressors supplying breathing air to respirators must be
constructed and situated to prevent entry of contaminated air into the air-supply system.
For example, air intakes must not be located on a loading dock because carbon monoxide
may be present. Suitable in-line air-purifying sorbent beds and filters are required to
further ensure breathing air quality. Sorbent beds and filters must be maintained and
replaced or refurbished periodically following the manufacturer's instructions. Examples of
sorbents include molecular sieves, charcoal, desiccants and hopcalite. OSHA also requires
that sorbents be periodically maintained following the manufacturer’s instructions and
further states: "Have a tag containing the most recent [sorbent] change date and the
signature of the person authorized by the employer to perform the change. The tag shall
be maintained at the compressor."
(1) If an air receiver is used to supply breathing air it must be maintained according to 29
CFR 1910.169, Compressed Gas and Compressed Air Equipment, Air Receivers.
(2) Reference 1 requires that oil-lubricated compressors must be equipped with high-
temperature or carbon monoxide alarms, or both, to monitor carbon monoxide levels.
If only high-temperature alarms are used, the air supply shall be monitored at intervals
sufficient to prevent carbon monoxide in the breathing air from exceeding 10 ppm.
Manufacturers of air compressors state in their equipment manuals what the
maximum allowable temperature is for their compressors.
(a) High temperature alarms are for the protection of the compressor, while carbon
monoxide monitor and alarm systems are for the protection of the worker. High
temperature alarms will not detect carbon monoxide entering the compressor at
the air inlet or produced inside the compressor. The locations of high temperature
alarms on compressors vary. When the alarm sounds depends on the location of
the alarm sensor. The respirator wearer could already be breathing carbon
monoxide by the time the high temperate alarm signals.
(b) To help emphasize the importance of controlling CO to safe levels in compressed
breathing air, Reference 10 is a National Institute for Occupational Safety and
Health (NIOSH) report of a worker’s death caused by breathing excess CO from
their airline respirator.
(3) Reference 1 states that the breathing air produced by non-oil lubricated compressors
must not contain carbon monoxide levels exceeding 10 ppm. This requirement can be
met by several different methods (or combination of methods) including the use of the
following:
(a) Continuous carbon monoxide monitors and alarm systems;
(b) Carbon monoxide filters;
(c) Proper air intake location in an area free of contaminants; or
(d) The use of high-temperature alarms and automatic shutoff devices, as appropriate.
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(4) Per Reference 9, electrochemical sensors used for periodic and continuous monitoring
of breathing air must be calibrated periodically, usually monthly, to perform accurately.
The measurement error for most electrochemical sensors is 5%. Color change
indicators cannot be used to detect the presence of carbon monoxide in breathing air.
The color change in the indicator is a warning of the presence of moisture in the
breathing air that is trapped in the filter, which can render the CO hopcalite filter
ineffective.
b. OPNAVINST 5100.23 Series - In addition to quarterly air quality monitoring to ensure
Grade D breathing air, Reference 4 requires compressor systems to be equipped with
either-high temperature or continuous carbon monoxide monitor and alarm systems or
both to monitor carbon monoxide levels. If only high-temperature alarms are used, the air
supply shall be monitored at intervals sufficient to prevent carbon monoxide in the
breathing air from exceeding 10 ppm. Furthermore, all new and/or upgraded air
compressor systems must be equipped with continuous carbon monoxide monitor and
alarm systems. Another requirement of this paragraph is to calibrate monitor and alarm
systems on compressors used for supplying breathing air according to the manufacturer's
instructions.
c. OPNAVINST 5100.19 Series - Per Reference 5, the compressor requirements include
quarterly testing to ensure Grade D quality before use and locating air intakes in clean air.
It states, “Ships shall equip compressor systems with either high-temperature or carbon
monoxide monitor and alarm systems or both, to control carbon monoxide levels. High-
temperature cut-off switches on fixed compressors, which shut down the compressor at a
temperature below which the lubricating oil breaks down (i.e., thermal degradation point),
meet the requirement for high-temperature alarms, provided that quarterly monitoring
meets the requirements for Grade D breathing air. Ships shall equip all new and/or
upgraded FIXED breathing air compressor systems with high-temperature cut-off switches.
New and upgraded portable breathing air compressor systems will be equipped or
operated with carbon monoxide monitor and alarm systems during SCBA air cylinder
charging operations. Calibrate monitor and alarm systems on compressors used for
supplying breathing air according to the manufacturer’s instructions.”
7. Breathing Air Couplings
a. Reference 1 requires that airline couplings be incompatible with outlets for other gas
systems. This prevents inadvertent servicing of airline respirators with non-respirable
gases or oxygen.
b. This paragraph also states that no asphyxiating substance shall be introduced into the
breathing air lines. For example, nitrogen cannot be used to blow the lines out.
8. Point Of Contact
Navy and Marine Corps Public Health Center
Industrial Hygiene Department
John Paul Jones Circle, Suite 1100
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Portsmouth, VA 23708-2103
DSN: 377-0700 or (757) 953-0700
FAX: (757) 953-0689
9. References
1.
29 CFR 1910.134, OSHA Respiratory Protection Standard
2.
CGA G7.1-1989, ANSI/Compressed Gas Association Commodity Specification for Air.
3.
CGA G-7.1-2018, Commodity Specification for Air. Seventh Edition.
4.
OPNAVINST 5100.23 Series, Navy Safety and Occupational Health Program Manual
5.
OPNAVINST 5100.19 Series, Navy Safety and Occupational Health Program Manual for
Forces Afloat
6.
Noonan GP, Linn HI, and Reed LD. (1986) A Guide to Respiratory Protection for the
Asbestos Abatement Industry, EPA publication no. DW75932235-01-1. Washington, D.C.:
U.S. Environmental Protection Agency, Office of Pesticide and Toxic Substances.
7.
ANSI/ASSE Z88.2-2015, Practices for Respiratory Protection.
8.
29 CFR 1910.134, OSHA Standard Interpretations
9.
Occupational Safety and Health Administration, Questions and Answers on the Respiratory
Protection Standard.
10.
National Institute for Occupational Safety and Health, Fatality Assessment and Control
Evaluation (FACE). Face 9131, Laborer Dies of Carbon Monoxide Poisoning During
Sandblasting Operations in Virginia.
