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Respirator Basics

Respirator Types - OSHA
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A respirator is a device that protects you from inhaling dangerous substances, such as chemicals and infectious particles. Respirators are among the most important pieces of protective equipment for working in hazardous environments.

Selecting the right respirator requires an assessment of all the workplace operations, processes or environments that may create a respiratory hazard. The identity of the hazard and its airborne concentrations need to be determined before choosing a respirator. This assessment should be done by experienced safety personnel or by an industrial hygienist.

Respirators work by:

  • filtering particles from the air,
  • chemically cleaning (purifying) the air, or
  • supplying clean air from an outside source.

1. When information regarding the exposure is limited, the decision should rely more heavily on _____.

a. consensus
b. professional judgment
c. common sense
d. what is available

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Respirator Types

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.
  • 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's 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 type of respirator supplies air from a safe source other than the ambient air?

a. Air-purifying respirator
b. N95 facepiece
c. Dust mask
d. Atmosphere-supplying respirator

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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's 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.

Non-Powered Air-Purifying Respirator (APR)

non-air purifying

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

Advantages

  • comparatively light weight
  • does not restrict mobility
  • provides both respiratory and eye protection

Disadvantages

  • 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. Which type of respirator would the user operate simply by breathing?

a. A powered air-purifying respirator (PAPR)
b. A non-powered air-purifying respirator (APR)
c. Supplied Air Respirator (SAR)
d. Self-Contained Breathing Apparatus (SCBA)

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Powered Air-Purifying Respirator (PAPR)

air purifying

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.

Advantages

  • 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.

Disadvantages

  • 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 respirator type is easy to breathe through and needs a fully charged battery to work properly?

a. A powered air-purifying respirator (PAPR)
b. A non-powered air-purifying respirator (APR)
c. Supplied Air Respirator (SAR)
d. Self-Contained Breathing Apparatus (SCBA)

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Atmosphere-Supplying Respirators

atmosphere supplying

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 respirator receives air from a connecting hose attached to a pressurized cylinder or an air compressor?

a. A powered air-purifying respirator (PAPR)
b. A non-powered air-purifying respirator (APR)
c. A supplied-air respirator (SAR)
d. A Self-Contained Breathing Apparatus (SCBA)

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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.

Advantages

  • 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.

Disadvantages

  • 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. Which type of respirator is not bulky and provides a positive-pressure air supply for a long periods?

a. A non-powered air-purifying respirator (APR)
b. A supplied-air respirator (SAR)
c. A dust mask respirator
d. A Self-Contained Breathing Apparatus (SCBA)

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Self-Contained Breathing Apparatus (SCBA)

engineering control

SCBAs have a full facepiece with an Assigned Protection Factor (APF) of 10,000. Fit testing is required.

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.

Advantages

  • 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.

Disadvantages

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

7. Which type of respirator is used for entry and escape from atmospheres that are considered immediately dangerous to life and health (IDLH) or oxygen deficient?

a. A non-powered air-purifying respirator (APR)
b. A supplied-air respirator (SAR)
c. A dust mask respirator
d. A Self-Contained Breathing Apparatus (SCBA)

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Are Dust Masks Respirators?


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While some people may call both respirators and facemasks "masks," this is incorrect as they are very different in their design, performance, and purpose. One important distinction that must be made when discussing respirator use is the difference between dust masks and respirators.

Dust masks are not NIOSH-approved disposable filtering face pieces. They can be worn for comfort against non-toxic nuisance dusts during activities like mowing, gardening, sweeping and dusting.

Only face masks certified by NIOSH are considered respirators by OSHA and covered under 1910.134 rules.

A NIOSH-certified face 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 discusses these differences in more detail.

8. What requirement must be met for dust masks to be considered respirators?

a. They must prevent 95% of common viruses from being inhaled
b. They must be certified by NIOSH and covered under 1910.134 rules.
c. They must be listed by and approved by OSHA and the AMA
d. They must be a positive pressure device with N95 filtering

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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. A poorly selected respirator can present can stress a worker's _____.

a. cognition and learning
b. eyes and heart
c. thyroid and lungs
d. heart and lungs

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Cleaning Respirators

cleaning

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 manager 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. Filter cartridges must be _____ respirator facepieces that have been cleaned.

a. stored separately from
b. color coordinated with
c. maintained inside
d. sufficient to be identified with

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