Respiratory Protection
Some of the most dangerous hazards you will encounter in the workplace are airborne. Many
areas in industrial facilities have low oxygen levels, and the air in some areas may contain
hazardous particles, gases, or vapors.
If you perform any job duties in these dangerous areas, respiratory protection equipment will
be vital to complete these tasks. Training in the identification of hazards and the proper use of
respiratory protection equipment can save your life.
After completing this course, you will be able to identify respiratory hazards and the types of
respirators that can protect you from each hazard. You will also know the key elements of an
effective respiratory protection program and how to properly use, maintain, and store
respiratory protection equipment.
Hazards
What are the major types of respiratory hazards?
Sources and effects
To protect against respiratory hazards, you should know not only what types of hazards you
may encounter, but how they affect you and where you might encounter them. Click on each
dot in the image below to learn more about the major types of respiratory hazards, their
possible sources, and their effects.
Particles
The air passages leading to your lungs contain cilia - small hairs that protect your lungs from many
contaminants. However, cilia cannot filter every contaminant, and some small particles can enter
your lungs and cause damage. Smoke, fumes, dusts (e.g., silica), fibers, and chemical mists are
considered hazardous particles. Those particles that are under 5 microns (1 micron = one millionth of
a meter) in diameter are the most hazardous, and you may need respiratory protection to keep
them out of your lungs.
Particles: Sources
Processes that can produce these particles include welding, grinding, sandblasting, combustion,
incineration, asbestos and fiberglass work, and even spray painting.
Particles: Effects
Depending on how toxic they are, particles can cause minor distress, allergic reactions, acute
respiratory distress, cancer, and even death.
Gases and vapors
Several areas in the workplace may contain toxic gases and vapors. You may need respiratory
protection in these areas to protect you from their harmful effects.
Gases and vapors: Sources
You may encounter some gases and vapors on a regular basis. For instance, chlorine and ammonia
are commonly used cleaning agents, and gas-powered engines produce carbon monoxide. Other
chemicals, such as benzene and vinyl chloride, have more specialized uses but are still common in
industrial facilities.
Gases and vapors: Effects
Some gases and vapors cause irritation and inflammation of the respiratory system. These are called
irritants and include chlorine and ammonia. Other gases and vapors can cause cancer. Known as
carcinogens, these include benzene and vinyl chloride. Still others can reduce the amount of oxygen
in the air and pose a suffocation risk. These are called asphyxiants and include nitrogen, carbon
dioxide, and carbon monoxide.
Oxygen deficiency
Normal breathing air is about 21% oxygen. Atmospheres that are less than 19.5% oxygen are
considered oxygen deficient. An oxygen-deficient atmosphere can cause death by asphyxiation.
Oxygen deficiency: Sources
Oxygen deficiency can occur in any location that is enclosed and has restricted airflow. Examples
include tanks, pits, mines, wells, and areas where the presence of certain chemical vapors displaces
the available oxygen in the air.
Oxygen deficiency: Effects
Decreasing levels of oxygen in the air can pose an increasing threat to your health and life. At oxygen
levels below 19.5%, you will begin to have vision, breathing, and coordination problems. At oxygen
levels below 17%, you will experience increasing adverse effects, such as impaired thinking, nausea,
vomiting, and unconsciousness. Continued exposure to oxygen levels this low can have irreversible
health effects and could be fatal.
IDLH environments
Immediately Dangerous to Life and Health (IDLH) environments are defined as
“environments with conditions that would pose an immediate or delayed threat to your life,
cause irreversible adverse effects to your health, or interfere with your ability to escape.”
These environments may include:
These environments present extreme forms of the hazards mentioned above and require
special precautions, which are discussed in greater detail later in this course.
Protection Program
What is a respiratory protection program?
Components
A good respiratory protection program contains an initial hazard assessment, written
procedures, designated administration, and training.
Hazard assessment
A hazard assessment determines which respiratory hazards are present. A company must perform a
hazard assessment to gain an understanding of the processes, equipment, raw materials, endproducts, by-products, and worker activities in the workplace.
Air monitoring
The hazard assessment may include air monitoring, which determines the amounts of harmful
substances that may be present in the working environment. The monitoring results are compared
to permissible exposure limits (PELs) for any harmful substances detected. A PEL is the maximum
amount of a harmful substance that you can legally be exposed to over a certain period of time. PELs
are set by regulatory agencies.
Reduction plan
If the hazard assessment reveals exposure above the PEL, your company must develop a plan to
reduce your exposure below these limits. The company accomplishes this through the use of
engineering controls, work practices, and respiratory protection, which we will discuss in this course.
Written procedures
Written procedures must be in place for:
 the selection, inspection, and use of respirators.
 the maintenance and repair of respirators.
 locations where respirator use is and is not required.
 equipment fit testing and medical evaluation.
 air quality standards for Supplied Air Respirators (SARs).
Designated administration
Your company should designate someone with special training and qualifications to administer the
company's respiratory protection program. This person is responsible for evaluating the program
regularly to ensure it is effective. You may be asked your opinion regarding the program's strengths
and weaknesses. Be sure to report any problems you have experienced.
Training
Prior to wearing a respirator and annually thereafter, you will receive respiratory protection training
based on the respiratory hazards in your work environment. The training will include information
about the type(s) of respirators selected for you, the proper use and limitations of each respirator,
routine and emergency use, and other information that will enable you to use the respirators
properly.
Respirators
What equipment will protect me from respiratory hazards?
Use, types, and hazards
Respirators provide safe breathing air through a face piece that covers your nose and mouth
and keeps out hazardous substances. To use a respirator, put on the face piece and breathe
normally, making sure the respirator maintains a
good seal to your face at all times.
Two types of respirators
Air Purifying Respirators
APRs filter or purify existing air so that harmful
substances do not enter your lungs. These
respirators are effective protection against particle,
gas, and vapor hazards.
Supplied Air Respirators
SARs provide an independent source of clean breathing air rather than filtering existing air.
An example is a Self-Contained Breathing Apparatus (SCBA). These respirators are effective
protection for environments that are Immediately Dangerous to Life and Health (IDLH), such
as an oxygen-deficient atmosphere.
Use the correct respirator
When you are performing a task in a hazardous environment, using the wrong
respirator can have devastating — even fatal — results. Make sure you use the
correct pre-selected respirator for the task you are performing. If you are ever
unsure about which respirator to use, check with your supervisor or program
administrator.
Prolonged use
Can prolonged breathing through respirators cause harm?
Answer
No. Breathing through respirators does not create a hazard, as long as you make sure your
selected respirator protects against the potential harmful contaminant in the air and you are
medically fit to use a respirator.
IDLH environments
IDLH environments include situations where:
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the level of oxygen is insufficient to sustain life.
substances are in concentrations high enough to cause death.
the hazards in the atmosphere are unknown.
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APRs
What should I know about Air Purifying Respirators?
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Based on hazards
APRs use cartridges and filters to purify the air before harmful substances can enter
your lungs. Your company will select the appropriate APR you will use, based on the
respiratory hazard to which you will be exposed.
Types of APRs
There are two types of APRs: particulate APRs and gas-and-vapor APRs. Particulate APRs use filters
to mechanically stop or remove particle hazards in the air. Remember that these APRs provide
protection ONLY against airborne particles. Gas-and-vapor APRs use chemical-absorbent cartridges
to clean the air of gas and vapor contaminants. Remember that these APRs provide protection ONLY
against gases and vapors.
Cartridges
Cartridges are color-coded and labeled according to the contaminant they remove. The table shown
here indicates the most common color codes for APR cartridges in the U.S.
Filters
APR filters, which can be used alone or with a cartridge, have both a rating and efficiency level. The
rating indicates how resistant the filter is to oil. Filters are coded with the letters N (not oil resistant),
R (oil resistant), or P (oil proof). The efficiency of a filter indicates the percent of airborne particles
that are stopped or removed from the air. The three levels of efficiency are 95%, 99%, and 99.97%,
which is rounded to 100%. Type 100 filters (i.e., filters that are 100% efficient) are sometimes
referred to as High Efficiency Particulate Air (HEPA) filters, which are capable of trapping 99.97% of
particles as small as 0.3 microns in diameter and can filter out dusts, mists, fumes, fibers, and even
some radioactive materials. Both P100 and HEPA filters have the color code magenta (purple),
making them easy to identify.
Identification
All filters and cartridges must be labeled and color-coded according to the National Institute for
Occupational Safety & Health's (NIOSH) standards. The label includes the word "NIOSH," the
manufacturer's name and part number, and an abbreviation to indicate the cartridge or filter type
(e.g., N95, P100). The abbreviation for a filter type combines the oil-resistant letter rating with the
efficiency level. For example, a filter marked with "R99" is somewhat resistant to oil and removes at
least 99% of the airborne particles. Filters marked "P100" are oil proof and remove almost 100% of
the airborne particles.
Face pieces
The two most commonly used face pieces are half-face and full-face. Your selection of a face piece
will depend on the shape of your face, the hazards around you, and input from your program
administrator. Cartridges and filters fit either face piece, as long as the face piece and the cartridge
(or filter) are from the same manufacturer and are appropriate for the respirator model.
Cartridge and filter replacement
Cartridge and filter replacement procedures are different for each type of APR. However,
keep the following guidelines in mind:
To learn how to replace the cartridge or filter on the respirator selected for your use, consult
with your supervisor or respiratory program administrator.
Further instructions
Make sure that you don’t mix different manufacturers’ respirator parts. Follow the
manufacturer’s instructions and any further cautions and limitations provided with
your APR. Also, make sure you follow your company’s site-specific procedures for APRs,
especially when you need additional protection against oil mist or lubricant spray (e.g.,
in a machine shop, near spray paint).
High Efficiency Particulate Air (HEPA)
Why does the Occupational Safety and Health Administration (OSHA) use the term
“HEPA” as a high efficiency rating when NIOSH uses “100”?
Answer
Although OSHA requires the use of NIOSH-certified respirators in its regulation, they still
use the term “HEPA filter” in many substance-specific standards. NIOSH uses N100, R100,
and P100 to identify high efficiency filters with an oil resistance rating.
SARs
What should I know about Supplied Air Respirators?
Use, limitations, and standards
SARs provide an independent source of clean breathing air that must meet certain standards.
SARs are effective when hazards are especially great. However, all SARs have certain
limitations, and each type of SAR has specific limitations due to the way it functions.
Types of SARs: Airline
An airline SAR has a stationary source of compressed air and provides this air to the user through a
hose. You will use an airline SAR when the task you must perform requires extended use of a
respirator.
Types of SARs: SCBA
In a Self-Contained Breathing Apparatus (SCBA), a limited amount of air is supplied through a
portable compressed air cylinder. SCBAs offer the highest level of protection of all respirators. SCBAs
are used when an airline SAR could be restricted or damaged by hazards (e.g., when fighting a fire)
or in Immediately Dangerous to Life and Health (IDLH) environments.
Limitations: Airline
Airline SARs can restrict your ability to move around freely. Maximum airline hose length may
restrict the use of devices with distance requirements. You must be careful when working around
obstructions or moving machinery; the airline hoses may snag and break. Also, airline respirators
provide no protection if the air supply fails. For IDLH atmospheres, you can use an airline respirator
if it is equipped with a separate bottle of air.
Limitations: SCBA
SCBAs can be heavy and bulky, restricting free movement. They also have a short service life. Most
provide between 30 and 60 minutes of air, and some emergency units may only provide 5 to 15
minutes of air. Strenuous work may decrease the amount of available air time. Also, extensive site
training is required for maintenance and safe use of SCBAs.
Air quality requirements: Air standards
The air in a SAR must be Grade D breathing air, as established by the American National Standards
Institute (ANSI) and the Compressed Gas Association (CGA). This will limit your exposure to carbon
monoxide, carbon dioxide, oil, and odors. This standard will also make sure you have enough oxygen
(19.5%-23.5%) available in the system.
Air quality requirements: Air compressor requirements
When the SAR supplies air through a compressor, the air intake must be away from contaminants,
such as cars and delivery vehicles. If the compressor is a non-oil-lubricated compressor, the carbon
monoxide (CO) concentration in the air it provides must not exceed 10 parts per million (ppm). If it is
oil-lubricated, you must use an alarm to warn of high CO levels, or use a CO monitor to make sure
the CO concentration remains below 10 ppm. All air compressors must have tags that indicate when
the air filters were changed and who performed the work.
Air quality requirements: Fitting and coupling requirements
Contaminants from non-breathing-air systems may lower the quality of air in a SAR. Therefore, all
fittings and couplings on SARs must be incompatible with non-breathing-air systems. This also
prevents connection to a cylinder of air or other gases that do not meet air quality standards for a
SAR.
Additional considerations
Most SARs do not provide protection against skin irritation and absorption hazards presented
by certain hazardous substances. Therefore, you may need a protective suit or similar
additional protection in certain areas. Also, SAR face pieces may present special problems
for individuals who must wear prescription lenses.
Regulations and site-specific procedures
You must always follow the manufacturer’s instructions and your company’s sitespecific procedures, as well as any further cautions and limitations, when using
your SAR. Take time to review these items before using this equipment.
Preparation
What must I do before using a respirator?
Crucial to health
Procedures to prepare for respirator use are crucial to maintaining your health. These
procedures will also give you confidence that your equipment will protect you against
hazardous atmospheres.
Medical evaluation
Your company will give you a medical screening questionnaire designed to identify medical
conditions that could affect your health while wearing a respirator. This information, along with a
copy of your company's respirator program, a copy of the respiratory protection regulation, and
specific information about your respirator use, will be provided to a company-identified physician
for a medical evaluation. Based on the questionnaire, the physician will determine if you require
medical monitoring while using a respirator or if another respirator may be more beneficial to you.
The physician will include this information in a written recommendation. Depending on your
condition and your hazard exposure, you may receive ongoing medical evaluations.
Fit testing
Many factors can affect how well a respirator fits, including scars, facial hair, weight gain or loss,
dental changes, and eyeglasses. Because of this, you will receive a fit test before you begin using a
respirator. The fit test should be repeated once a year to make sure that your respirator still fits well
and the face piece maintains a good seal. Additional fit testing will be required if your physical (e.g.,
facial) characteristics change or if you, your supervisor, or your program administrator thinks there
may be respirator leakage.
Qualitative Fit Testing (QLFT)
The QLFT determines your reaction to a substance while you are wearing the respirator. A relatively
harmless material (sweet or bitter-tasting substances, such as saccharin or irritant smoke) is placed
into the atmosphere around your respirator. If you do not smell, taste, or react to the substance,
then it did not enter the respirator and the fit is good.
Quantitative Fit Testing (QNFT)
The QNFT uses a machine that measures and compares concentrations of contaminants inside and
outside your respirator. When the measurement inside the respirator mask has lower predetermined levels than the level outside the respirator, then the fit is good.
User seal checks
You must perform seal checks to make sure you have a good seal each time you put on your
respirator. These include negative and positive pressure checks. If a good seal is not maintained
during either check, contact your supervisor to see if you must undergo additional fit testing.
Negative pressure check
To do a negative pressure check, seal the respirator cartridges, breathe in through your nose or
mouth, and hold your breath for 10 seconds. If the respirator has a good seal, the face piece will
collapse slightly and no air will enter around the seal. If the respirator does not have a good seal, air
will leak through and the face piece will not collapse inward.
Positive pressure check
To do a positive pressure check, seal the exhalation valve and blow air out slightly through your nose
or mouth. If the respirator has a good seal, then some pressure builds up inside the face piece
without any outward air leakage at the seal. If the respirator does NOT have a good seal, air will leak
past the face piece, and you will need to reposition the face piece or adjust the straps.
Site-specific training
You will receive site-specific training before the first time you wear a respirator in a hazardous
environment and at least once a year after that. This training will include hands-on experience and
site-specific details about routine and emergency respirator use, storage and maintenance
procedures, cartridge replacement procedures, limitations of each respirator type, and medical signs
and symptoms of contaminant exposure. Make sure you understand all the material. Alert your
supervisor if anything is unclear to you.
Certification
All respirators must meet criteria established by the National Institute of Occupational Safety
and Health (NIOSH). Every respirator must be tested and certified before use and will receive
a Tested and Certified (TC) number. You cannot use a respirator that does not have a TC
number.
Respirator failure
If you ever detect signs of respirator failure (e.g., a leaking face piece) or if you feel,
taste, or smell chemicals in the air, you should always leave your work area
immediately and consult your supervisor or program administrator. If you experience
irritation, immediately wash your face thoroughly.
Maintenance
How can I keep respirators in good condition?
Ready for use
Proper cleaning and storage ensures that a respirator will be ready for use when you need it.
Cleaning
If respirators are shared, then they must be cleaned and disinfected after each use. If a respirator is
assigned to only one person, it must be cleaned and disinfected as often as you deem it necessary.
Cleaning before each use is a good rule to follow. Your supervisor will explain the specific procedures
for cleaning and disinfecting your respirator. Make sure you follow these procedures, and notify
your supervisor if you are unclear about how or when to do this.
Storage
When not in use, respirators must be stored in a designated area that is marked, clean, and quickly
accessible. The area must keep the respirators away from dust, dirt, sunlight, temperature extremes,
damaging chemicals, and excessive moisture. All respirators must be stored in either a sealed plastic
bag hanging on the wall or a designated respirator room or cabinet. They must also be properly
labeled for use; labeling information includes inspection dates for emergency use respirators.
Inspection
What should I know about respirator inspection?
Requirements
Your employer will check some of the parts of your respirator periodically to make sure it is
functioning properly. However, you should also check the parts of the respirator and follow
the manufacturer’s recommendations.
Inspection procedures and documentation are similar for most respirators, but inspection
schedules can differ greatly.
Face piece, head straps, and valves
Check the face piece for scratches, cracks, tears, holes, distortion, and a lack of flexibility. Look for
broken, missing, badly worn, or incorrectly mounted parts, especially clips and lenses. Check the
head straps for loss of elasticity, stretched or broken straps, broken buckles or attachments, and
worn parts on head harnesses. Look for foreign materials (e.g., hair or dust particles) in valves. Also,
look for any missing or defective valve covers, improper valve installation, or cracks, breaks, or chips
in the valve body.
Connections and connecting tube
Make sure all parts are tightly connected. Look for broken or missing tube connectors or clamps.
Stretch the connection tube and look for cracks, which would indicate deterioration.
Cartridges, canisters, or filters
Make sure the cartridge, canister, or filter in the respirator is appropriate for the hazard and has not
expired. Check the holder for incorrect installation, loose connections, missing gaskets, and cross
threading. Look for cracks, dents, extra holes, or tape on the outside, especially over the inlet.
Compressed air
Compressed air cylinders should be at 100% capacity when they arrive for use. Check these cylinders
periodically to make sure the levels do not fall below 90%. If they do, notify your supervisor.
Compressed air cylinders must be periodically tested professionally prior to refilling. The frequency
for testing is based on the type of material used in construction of the cylinder.
General requirements
All respirators should be inspected before being brought into the workplace. In addition, you should
inspect respirators on various schedules based on how often they are used.
Routine use
Respirators that are used for everyday tasks (e.g., welding) should be inspected before and after
each use and during cleaning.
Non-routine-use
Some respirators are used in non-routine (e.g., emergency) situations. These respirators, which
include SCBAs and airline SARs as well as emergency escape packs, must be inspected:
 at least monthly, or according to the manufacturer's recommendations.
 before and after each use.
Types of documentation
Inspections must be documented. Documentation should be in the form of a tag or label attached to
the respirator's storage compartment. It should also be included in the inspection reports. In some
cases, electronic files recording inspection can also be used.
Required information
The tag or label on a respirator should include the date of inspection, the name of the person who
performed it, the serial number of the respirator (or other identification), and the results (including
any required action).
Removing defective respirators
Respirators found to be defective must be tagged, removed from service, and discarded,
repaired, or adjusted. Authorized repair persons must use only the manufacturer’s NIOSHapproved parts. Contact your program administrator to learn about your company’s
replacement procedure.
IDLH
What additional precautions must I take in IDLH environments?
Right equipment and personnel
In any hazardous situation, you should have access to the right equipment and personnel so
that you can escape safely and quickly if an accident occurs. In Immediately Dangerous to
Life and Health (IDLH) environments, this access becomes even more crucial. Remember, an
IDLH environment means that the surrounding hazards may pose an immediate threat to your
life.
Adequate respirator
You must have an adequate respirator to supply you with fresh, uncontaminated air. This could be a
pressure-demand SCBA (one that always contains a slight amount of positive pressure inside the
facepiece so contaminants cannot get inside) or a pressure-demand airline SAR with an emergency
escape bottle.
Standby employees
One or more trained employees must be located outside the IDLH atmosphere, standing by to
provide effective emergency rescue. These equipped persons must have:
 pressure-demand SARs or SCBAs.
 appropriate retrieval equipment.
 visual, voice, or signal line communication equipment.
Designated person
There must be a procedure in place to notify a designated person when one of the equipped persons
must enter to provide an emergency rescue. This ensures that at least one person is aware of your
presence in the area as well as the rescue worker's presence. The designated person can provide
backup assistance as well, if needed.
IDLH, unless proven otherwise
IDLH areas do not just contain harmful chemicals. They may also lack sufficient oxygen
or have unknown contents. Therefore, unless you know the oxygen level and the
contents of an enclosed area, you should always consider it IDLH until you can prove
otherwise.
Structural firefighting
The requirements for entering IDLH environments are more stringent when you
and your coworkers are involved in structural firefighting. If you are involved in
this work, check with your supervisor about these requirements.