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Respirator fit testing

Workers with inhalation exposures from harmful substances, including chemical, biological, and radiological agents, are required by the Occupational Safety and Health Administration (OSHA) to wear respiratory protection. Some forms that dangerous airborne particulates can take are:

  • Vapors
  • Gases
  • Dust
  • Fogs
  • Fumes
  • Mists
  • Smokes
  • Sprays

Employers must provide respirators for exposed workers that create a seal from inhalants to isolate the user’s respiratory system from the contaminated environment. Devices vary to protect users from a variety of substances, and they function by purifying the air or supplying clean air. OSHA requires employers to select respirators that will adequately protect their workers and conduct fit testing prior to use.

Types of respirators

All tight-fitting respirators worn by workers are subject to the requirements of OSHA’s Respiratory Protection Standard 1910.134. Below are different types of respirators that employers may select for use in their workplace.

Air-purifying respirators

Particulate respirators – capture particles in the air, such as dusts, mists, and fumes (includes N95 and other dust masks)

Combination respirators – used in atmospheres that contain hazards of both particulates and gases

Gas and vapor respirators – used when there are only hazardous gases and vapors in the air

Atmosphere-supplying respirators

Air-supplied respirators – makes use of a hose to deliver clean, safe air from a stationary source of compressed air; used when there are extended work periods required in atmospheres that are not immediately dangerous to life and health

Combination respirators – have an auxiliary self-contained air supply that can be used if the primary supply fails; used for entry into confined spaces

Self-contained breathing apparatus – consists of a wearable, clean-air supply pack; used when there is a short-time need to enter and escape from atmospheres

Purpose of fit testing

A respirator fit test is a procedure to evaluate the fit of a respirator on an individual. Since the size and shape of people’s faces and necks are unique, the same device will not protect all users. If a respirator is not fitted correctly, the device may leak, allowing the user to breathe in contaminated air. One way to prevent this mishap is to perform a fit test on each user to ensure that their respirator is tight-fitting and creates the proper seal.

When to test

According to OSHA, employees required to wear respirators must be fit tested each time one of the following conditions applies:

  • Prior to being allowed to wear any respirator with a tight-fitting facepiece
  • Annually
  • When there are changes in the employee’s physical condition that could affect the fit of a respirator (i.e., obvious change in body weight, major dental work, facial surgery or scarring)
  • When a different respirator facepiece (size, style, model, or make) is used

Fit testing on a regular basis, as well as when a user experiences changes that can affect the fit of the respirator, will ensure that workers are protected from inhaling harmful substances. When conducting testing, employers must also use the exact make, model, and size of the respirator that users will wear in the workplace.

Types of fit tests

There are two types of fit tests for respiratory protection: qualitative and quantitative.

Qualitative fit testing is a pass/fail test method that uses a worker’s sense of taste or smell or their reaction to a substance to detect leakage into the respirator facepiece. Qualitative methods do not measure the actual amount of leakage in the respirator. This type of test is typically conducted for half-mask respirators, which only cover the user’s face and mouth. A common example of a half-mask device is an N95 respirator.

Quantitative fit testing uses a machine to measure the actual amount of leakage into the facepiece. A probe connects the respirator to a machine that determines the numeric value associated with leakage into the mask. Quantitative tests are appropriate for most types of tight-fitting respirators.

Medical evaluations

Before performing a fit test on a worker, employers need to conduct initial medical evaluations to determine if the individual will be able to wear and use a respirator safely. OSHA states that employers must identify a physician or other licensed health care professional to perform medical evaluations using a questionnaire or an initial examination. Appendix C of Standard 1910.134 provides the required information for a medical questionnaire.

Once completed by a worker, this document provides critical information regarding the individual’s experience with respirators, existing medical conditions that may interfere with their ability to use a respirator, and physical abilities that are essential for proper use of respiratory protection. The consulting physician or licensed health care professional may then decide whether or not to issue a recommendation for the worker to wear a respirator. Once approval for the recommendation is obtained, the employer may begin fit testing.

Respirator training and recordkeeping

In addition to selecting the correct respirator for workers and conducting fit tests, employers must train employees on the proper use of the devices, perform regular recordkeeping duties, and develop a written program to document all elements of respiratory protection.

OSHA requires workers to receive annual training on the following subjects:

  • Why respirators are necessary and how improper fit, usage, or maintenance can compromise the protective effect of a respirator
  • The limitations and capabilities of the respirator
  • How to use the respirator effectively in emergencies, including situations in which the respirator malfunctions
  • How to inspect, put on and remove, use, and check the seals of the respirator
  • The procedures for maintenance and storage of the respirator
  • How to recognize medical signs and symptoms that may limit or prevent the effective use of respirators
  • Applicable respiratory protection regulations Records for each worker requiring protection should be maintained and include the following information:
  • Employee name
  • Date of fit test
  • Type of test
  • Type, model, and size of respirator used for testing
  • Results of the test
  • Date of training
  • Subjects addressed in training

These records should supplement the formal, written respiratory protection program maintained by the employer. Basic elements to include in the program as directed by OSHA are:

  • Procedures for selecting respirators
  • Medical evaluations of workers required to use respirators
  • Fit testing procedures
  • Use of respirators in routine situations and potential emergencies
  • Procedures and schedules for cleaning, disinfecting, storing, inspecting, repairing, and maintaining respirators
  • Procedures to ensure adequate air quality, quantity and flow of breathing air for self-contained breathing apparatus
  • Training employees in the respiratory hazards to which they are potentially exposed
  • Training employees in the proper use of respirators
  • Procedures for regularly evaluating the effectiveness of the program

The list above provides a general overview of program components. Please refer to OSHA Standard 1910.134 for specific requirements, and consider contacting a qualified safety professional to evaluate your company’s program.

Additional information and guidance for respiratory protection can be found at the following links: