Course 614 Personal Protective and Lifesaving Equipment

Respiratory Protection

The purpose of a respirator is to prevent the inhalation of harmful airborne substances and/or an oxygen-deficient atmosphere. A respirator is designed as an enclosure that covers the nose and mouth or the entire face or head.

Respirators are available in many types, models, and sizes from several manufacturers for a variety of applications. Different types of respirators are designed to provide different levels of protection and to protect against different hazards.

The type of respirator to be used depends on several considerations:

  • professional judgment,
  • the type of airborne contaminant, its concentration, and potential to cause a health effect in exposed personnel, and
  • applicable regulations.

When information regarding the exposure is limited, the decision should rely more heavily on professional judgment and more protective respirators may be selected for use.

Each facility’s written policies and training programs should specify whom to contact for questions or additional information.

Examples of Respiratory Hazards

Particulates: These are airborne particles such as dust, fibers, fumes, mists, soot, and smoke. Some are so small they can only be seen with an electron microscope. The diameter of a particulate is usually measured in micrometers (one micrometer equals 1/1,000 millimeter or 1/25,400 inch). Particles with diameters under 10 micrometers are more likely to enter the respiratory system.

Gas and vapors: Gases can spread freely in the air. Vapors are the gaseous states of substances that are liquids or solids at room temperature. Gases and vapors are classified by their chemical forms.

Biological organisms: These include bacteria, viruses, fungi, and other living organisms that can cause respiratory infections.

Oxygen-deficient atmosphere: Normal air has an oxygen concentration of 20.8 percent by volume. When the concentration drops below 19.5 percent, the air is oxygen deficient and considered immediately dangerous to life and health (IDLH). The harmful effects of oxygen deficiency include impaired thinking and coordination, unconsciousness, and death.

1. At what concentration of oxygen is air considered oxygen deficient?

a. Below 13.5 percent
b. Below 16 percent
c. Below 19.5 percent
d. Below 21 percent

Respirator Types

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To understand how respirators can be used to protect employees, it is important to understand what a respirator is and what it is not. A respirator protects against respiratory hazards by removing specific air contaminants from the ambient (surrounding) air or by supplying breathable air from a safe source.

  • Air-purifying respirators: Respirators that remove contaminants from the ambient air are called air-purifying respirators. Particulate respirators are a type of air-purifying respirator. The part of a respirator that forms a protective barrier between the user’s respiratory tract and air contaminants is called an inlet covering. Most inlet coverings are classified as either tight-fitting or loose-fitting.
  • Tight-fitting respirator: A tight-fitting respirator has an inlet covering, also called a face piece or mask, designed to form a seal with the face of the wearer. It is available in three types: quarter mask, half mask, and full face piece.
  • air purifying
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  • Loose-fitting respirator: A loose-fitting respirator has an inlet covering that typically covers the user’s head and may extend over the shoulders. It is designed to form a partial seal with the face. These include loose-fitting face pieces, as well as hoods, helmets, blouses, or full suits, all of which cover the head completely.
  • Atmosphere-supplying respirators: Respirators that supply air from a safe source other than the ambient air are called atmosphere-supplying respirators. There are two types of atmosphere-supplying respirators: Supplied-Air Respirators (SARs) and Self-Contained Breathing Apparatus (SCBA).

Air-Purifying Respirators (APR)

The air-purifying respirator, or “APR,” has an air-purifying filter, cartridge, or canister that removes specific air contaminants, such as particulates, gases, and vapors, or both from the air.

Selecting an appropriate filter, cartridge, or canister can be complicated because there are many types, and none protect against all contaminants. That is why it’s necessary to identify each respiratory hazard in your workplace before you select a respirator.

Air-purifying respirators are available in non-powered and powered types. We will discuss these two types of respirators in the next couple sections.

2. Which respirator removes specific air contaminants, such as particulates, gases, and vapors, or both from the air?

a. Atmosphere-Supplying Respirator (ASR)
b. Air-Purifying Respirators (APR)
c. Self-Contained Breathing Apparatus (SCBA)
d. Tight-Fitting Respirator (TFR)

Non-Powered Air-Purifying Respirator (APR)

Non-Atmosphere-Supplying Respirators
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When using a non-powered air-purifying respirator, the user operates it simply by breathing.

There are basically three types of non-powered APRs:

  • Half mask/Dust mask
  • Half mask (Elastomeric)
  • Full face piece (Elastomeric)

Key Features

  • elastic face piece covers entire face
  • inspiratory effort of wearer draws ambient air through filter(s) before air is inhaled
  • provides increased protection when used with filters, cartridges, or canisters that remove specific contaminants


  • Comparatively light weight.
  • Does not restrict mobility.
  • Provides both respiratory and eye protection.


  • Does not supply oxygen (cannot be used in low oxygen environments).
  • May only be used when air contaminant level is below the concentration limits of the filter(s).
  • Fit testing required.
  • Some contaminated air can leak into facepiece.
  • Communication can be difficult.

3. What is a major disadvantage of non-powered air-purifying respirators (APRs)?

a. They are not a true positive-pressure devices.
b. They are dependent on batteries.
c. They are bulky and noisy.
d. They do not supply oxygen.

Powered Air-Purifying Respirator (PAPR)

Powered Air-Purifying Respirators
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This type of respirator has a blower that forces ambient air through one or more filters attached to an inlet covering. The powered type is easier to breathe through than the non-powered type but needs a fully charged battery to work properly.

Key Features

  • Battery powered blower forces contaminated ambient air through air-purifying filters.
  • Purified air is delivered under positive-pressure to facepiece mask, helmet, or hood.
  • Worn when disposable and reusable half mask negative-pressure air-purifying respirators do not provide adequate protection.


  • Provides greater protection than non-powered negative-pressure air-purifying respirators.
  • More comfortable to wear and to breathe compared to non-powered negative-pressure air-purifying respirators.
  • Air delivery to facepiece mask, helmet, or hood ensures that leakage of contaminated air is usually outward.
  • Fit testing is not required.
  • Various chemical cartridges or canisters are available to eliminate chemicals including organic vapors and acid gases.
  • Provides both respiratory and eye protection.


  • bulky and noisy
  • battery dependent
  • not a true positive-pressure device (i.e., some leakage of contaminated air into facepiece mask, helmet, or hood can occur)
  • communication can be difficult

4. Which of the following is an advantage of powered air-purifying respirators (PAPRs)?

a. They are less bulky and noisy
b. They do not require fit testing
c. They do not restrict mobility
d. They require less protection
Atmosphere-Supplying Respirators
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Atmosphere-Supplying Respirators

Atmosphere-supplying respirators are used to provide breathing air from a source independent of the ambient atmosphere. Respirators that supply breathing air are generally used in highly hazardous work environments. It is critical that such respirator systems provide breathing air of optimal quality and that the equipment operates reliably.

The two types of atmosphere-supplying respirators are:

  • Supplied-air respirators (SARs) (also known as airline respirators), receive air from a connecting hose. The source of air is either a pressurized cylinder or an air compressor. Because the employee does not carry the air on his or her back when using a SAR, breathing air can be provided over a longer time period than is the case with an SCBA.
  • Self-contained breathing apparatus (SCBA) units: Air is supplied from a tank (a cylinder of compressed air or oxygen). For this type of respirator, the source of the breathing air is designed to be transported by or with the equipment user.

5. Which type of atmosphere-supplying respirator can provide air for a longer period of time?

a. Air-purifying respirator (APR)
b. Tight-fitting respirator (TFR)
c. Supplied-air respirator (SAR)
d. Self-contained breathing apparatus (SCBA)

Supplied-Air Respirator

Donning a Supplied Air Respirator – IUOE NTF
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Key Features

  • Compressed air is delivered from a stationary source (located away from contaminated area) to a half or full facepiece mask via a hose.
  • Worn when negative-pressure and powered air-purifying respirators do not provide adequate protection.


  • Provides high level respiratory protection.
  • Provides positive pressure to mask so almost all leakage is outward.
  • Less bulky and can be used for longer periods than self-contained breathing apparatus.
  • May be easier for hospital personnel to use.
  • Provides both respiratory and eye protection.


  • Length of air hose may limit mobility.
  • Air hose may be a trip hazard.
  • Clean source of breathing air is required.
  • Fit testing is required.
  • Immediately operable emergency escape respirator, escape hood, or escape mask is required.
  • Communication can be difficult.

6. What is a major disadvantage of supplied-air respirators?

a. They require escape respirator, hood, or mask
b. They are difficult for healthcare workers to use
c. They are not a true positive-pressure device
d. They provide a low level of respiratory protection

Self-Contained Breathing Apparatus (SCBA)

Chart for APF
Assigned Protection Factors
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SCBAs have a full facepiece with an Assigned Protection Factor (APF) of 10,000. APFs are used to select the appropriate class of respirators that will provide the necessary level of protection.

Key Features

  • Provides very pure, dry compressed air to full facepiece mask via a hose.
  • Air is exhaled to the environment.
  • By law, this type of respirator must be worn whenever entering environments immediately dangerous to life and health (IDLH) or when information is inadequate to rule out IDLH atmosphere.
  • Fit testing is required.


  • Provides highest level of respiratory protection.
  • Several different types are available depending on need.
  • Offers improved mobility over Supplied-Air Respirators.
  • Provides both respiratory and eye protection.


  • They are heavy to wear.
  • Limited oxygen supply limits the duration of use.
  • Fit testing is required.
  • Communication can be difficult.

7. By law, which type of respirator must be worn whenever entering an IDLH environment or when information is inadequate to rule out an IDLH atmosphere?

a. Air-purifying respirator (APR)
b. Tight-fitting respirator (TFR)
c. Supplied-air respirator (SAR)
d. Self-contained breathing apparatus (SCBA)

Are Dust Masks Respirators?

One important distinction that must be made when discussing respirator use is the difference between respirators and facemasks. Facemasks include surgical masks, which are fluid resistant, and procedure or isolation masks which are not fluid resistant.

While some people may call both respirators and facemasks "masks," this is incorrect as they are very different in their design, performance, and purpose.

Only dust masks certified by NIOSH are considered respirators and are covered under 1910.134 rules. A NIOSH-certified dust mask – called a filtering facepiece – is a tight-fitting, negative pressure, particulate respirator. The particulate filter is the facepiece. Dust masks that don't have NIOSH certification are not respirators.

The video to the right helps to explain the differences between respirators and facemasks.

8. Which of the following is NOT a characteristic of a NIOSH-certified dust mask?

a. positive pressure
b. negative pressure
c. tight fitting
d. filters particulates

Next Section

Respirator Selection

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Properly selected and used, respirators protect workers from hazards but don't eliminate hazards. If the respirator fails or is inappropriate for a particular task, the user risks exposure. A respirator can stress a worker’s heart and lungs and present other physical and psychological challenges such as:

  • Breathing through a tight-fitting air-purifying respirator, for example, is harder than breathing ambient air.
  • An atmosphere-supplying self-contained breathing apparatus (SCBA) can increase the user’s heart rate because of its weight.
  • Those with lung diseases or asthma or who have trouble breathing should never use a respirator without the approval of a professionally licensed-health care provider (PLHCP).
  • Those who have vision problems or who are claustrophobic may also be unable to use some respirators.

Effective respiratory protection ensures that workers are medically able to use respirators, that their respirators fit properly, and that they know how to use and care for their respirators.

Respirator Care and Maintenance – OSHA
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Care and Maintenance of Respirators

Employees must clean and inspect their own respirators in accordance with the provisions of the respiratory protection program. Here are some important things to remember:

  • Maintenance involves a thorough visual inspection for cleanliness and defects.
  • Worn or deteriorated parts must be replaced prior to use.
  • No components are to be replaced or repairs made beyond those recommended by the manufacturer.
  • Repairs to regulators or alarms of atmosphere-supplying respirators are to be conducted by the manufacturer.

9. Employees with lung diseases or asthma or who have trouble breathing should _____.

a. only use N-95 respirators for most applications
b. change the type of respirator being used
c. minimize the use of full-face respirators
d. never use a respirator without the approval of a PLHCP

Cleaning Respirators


Cleaning and sanitizing respirators is necessary to prevent skin irritation and dermatitis. Contaminant build-up on the respirator facepiece seal or within the respirator can reduce the protection because the contaminant is in the breathing zone or has compromised the seal. Contamination can also contribute to the deterioration of the respirator's materials. Also, follow these cleaning best practices:

  • Respirators must be cleaned and disinfected as often as necessary to remain sanitary.
  • Respirators used by more than one employee must be cleaned and disinfected before being used by a different individual.
  • Respirators maintained for escape-only use, as well as respirators used in fit testing and training, must be cleaned and disinfected after each use.

The program administrator should maintain an adequate supply of the appropriate cleaning and disinfecting agents at the cleaning station.

Storing Respirators

After inspection, cleaning, and necessary repair, store respirators so that they are not damaged, contaminated, or exposed to dust, sunlight, extreme temperatures, excessive moisture, and damaging chemicals. Follow these procedures to store respirators properly:

  • Store filter cartridges separately from clean respirator face pieces to prevent contamination of the interior of the respirator facepiece from hazardous particulate matter (e.g., lead, asbestos, cadmium, silica) that may have accumulated on the filter cartridge.
  • Store the facepiece and the exhalation valve in a manner that will prevent deformation. To do that, position each respirator so it retains its natural configuration. Synthetic materials and even rubber will warp if stored in an unnatural shape, thus affecting the fitting characteristics of the facepiece.
  • Respirators should be packed or stored so the facepiece and exhalation valve will rest in a normal position and function will not be impaired by the elastomer setting in an abnormal position.

10. Which of the following is correct when storing respirators?

a. Fold face pieces inside-out to keep them clean
b. Store respirators to prevent deformation of parts
c. Make sure they are stored by a hook on a wall
d. Place respirators tightly in metal boxes

Identification of Filters, Cartridges, and Canisters

Image of respirator military photo 161207-F-JZ707-002
Respirator with cartridges.

A canister or cartridge is a container with a filter, sorbent, or catalyst, or combination of these items, which removes specific contaminants from the air passed through the container. The employer must ensure that all filters, cartridges and canisters used in the workplace are labeled and color coded with the NIOSH approval label and that the label is not removed and remains legible.

To fulfill these requirements, you should adopt appropriate procedures for ensuring that:

  • only NIOSH-certified filters, cartridges and canisters are used, and
  • labels are not removed, defaced, or obscured during respirator use.

What is on the label: The label clearly states the class of contaminants for which the filter, cartridge, or canister may be used (e.g., permissible particulate respirator filter for dusts, fumes and mists, including asbestos-containing dusts and mists and radionuclides. The NIOSH certification number and any limitations or precautions are also included on the label.

Purpose of the label: The NIOSH label serves several purposes. It ensures selection of the appropriate cartridge/canister for the contaminants found in the workplace. Also, it permits the employee using the respirator to check and confirm that the respirator has the appropriate filters before the respirator is used. The color coding scheme allows fellow employees, supervisors and the respiratory protection program administrator to readily determine that the worker is using the appropriate filter.

11. What method is used to make it easy for employees to determine a worker is using the appropriate filter?

a. Daily inspections
b. Quarterly NIOSH bulletins
c. A color coding system
d. A thorough canister sign-out procedure

Check your Work

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Optional Video

This U.S. Department of Labor video covers respirator safety. When you must wear a respirator to protect yourself against airborne contaminants in your workplace, it is very important to follow proper procedures for putting it on and taking it off.

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