Respiratory protection

Respirator fit test requirements

Getting a better grasp on this complicated topic

Image: U.S. Navy

Lisa Brosseau has taught or consulted on respiratory protection for about three decades. Yet some aspects of it are unclear even to her.

“That’s how complicated the topic can be,” said the industrial hygiene consultant and former professor at the universities of Minnesota and Illinois at Chicago. “There’s just a myriad of things with respirators that people don’t really understand.”

Fit testing is one of the more challenging components, she said.

Lack of fit testing was cited among the 2,826 respiratory protection violations OSHA issued in fiscal year 2019, Patrick Kapust, deputy director of the agency’s Directorate of Enforcement Programs, announced during the National Safety Council 2019 Congress & Expo in September. The Respiratory Protection Standard (1910.134) ranked fifth on the list of OSHA’s “Top 10” most frequently cited standards.

“You’ve got to make sure for tight-fitting respirators that they have the appropriate fit for the employee,” Kapust said.


Why do some employers fail to follow fit testing requirements? For “several reasons,” an OSHA spokesperson wrote in an email to Safety+Health. Among them:

  • Lack of awareness of the standard’s requirements
  • A feeling that the requirements are too cumbersome
  • Uncertainty over which testing methods to use for certain respirators
  • Time and cost
  • Forgetting to conduct annual fit test because of “rotation” of employees and/or supervisors

Larry Janssen, former chair of the American Industrial Hygiene Association’s Respiratory Protection Committee and an industrial hygienist, said smaller organizations often aren’t aware that tight-fitting respirators must be fit tested. In larger organizations, “individual facilities sometimes overlook their company’s respirator program requirements.”

James Johnson, an industrial hygiene consultant and chair of the respiratory subcommittee of ASTM International’s committee on personal protective clothing and equipment (F23), said some employers may not have a complete understanding of the time, resources and other aspects involved with protecting workers from respiratory hazards.

“Fit testing and the overall effective use of a respirator is a package deal,” Johnson said. “It’s not just, ‘I’ll buy a respirator and then [be] OK.’ That’s like buying a car and not putting gas in it.”

Basic OSHA requirements

OSHA requires the use of respirators to keep workers from breathing contaminated air and protect them from oxygen deficiency when effective engineering controls aren’t feasible.

“The Hierarchy of Controls says we should be doing absolutely everything you can to make it such that people don’t need respirators,” Brosseau said. “The OSHA standard actually requires that you have done all of those things and demonstrate prior, major and best efforts. And then, and only then, are you actually allowed to use respirators.”

Respirators come in two major types: air-purifying and air-supplying. For respirators that are required (not voluntary) and need to form a protective seal over part or all of the user’s face – known as a tight-fitting facepiece respirator – an initial medical evaluation is required before a fit test, along with a written respiratory protection program. Unlike a fit test, this evaluation is not required every 12 months, but certain situations may arise in which another evaluation is warranted. According to the OSHA regulations, such circumstances include:

  • A change in workplace conditions, such as temperature or increased physical workload, occurs that will place a greater “physiological burden” on a worker.
  • A physician, licensed health care practitioner, supervisor or respiratory program administrator informs a worker that he or she needs to be reevaluated.
  • A worker reports medical symptoms or signs related to his or her ability to use a respirator.

Additionally, a written respiratory protection program must ensure any worker voluntarily using a respirator is “medically able,” and that respirators are properly cleaned, stored and maintained. One exception is the voluntary use of filtering facepiece respirators in work areas with no respirable hazards.

The type of respirator needed for a job should correlate with the type of hazard(s) (e.g., vapors, mists, fumes, oxygen deficiency or a combination of hazards) to which the worker is exposed. This is why a proper hazard assessment is essential.

Respirators should be NIOSH-certified, and employers must provide worksite-specific training. Fit testing for the equipment takes one of two forms, qualitative or quantitative, and should not be confused with a user seal check – a quick test performed at the beginning of each workday.

How fit tests work

Qualitative fit testing uses the wearer’s sense of smell or taste, or his or her reaction to an irritant, to determine whether a proper seal is achieved. This testing is done on a subjective, pass-fail basis, with the wearer either detecting the substance or not.

OSHA considers four types of qualitative testing methods acceptable:

  • Bitrex (leaves a bitter taste in the mouth)
  • Irritant smoke (can cause coughing)
  • Isoamyl acetate (smells like bananas)
  • Saccharin (leaves a sweet taste in the mouth)

Quantitative testing uses a machine or computer to measure leakage into the facepiece. A probe is attached to the facepiece and connected to the machine by a hose. Acceptable quantitative tests, according to OSHA, are:

  • Ambient aerosol condensation nuclei counter
  • Controlled negative pressure
  • Generated aerosol
  • Modified ambient aerosol condensation nuclei counter for full- and half-facepiece elastomeric respirators
  • Modified ambient aerosol CNC for filtering facepiece respirators

OSHA approved the last two testing methods listed in a final rule published Sept. 26. They are variations of the original OSHA-approved ambient aerosol CNC protocol, but have “fewer test exercises, shorter exercise duration and a more streamlined sampling sequence,” a Sept. 25 press release from the agency states.

Qualitative vs. quantitative

According to the OSHA 1910.134(f)(6) provision, qualitative fit testing “may only be used to fit test negative pressure air-purifying respirators that must achieve a fit factor of 100 or less.” This, Johnson noted, is because the current qualitative test methods only can detect or “reproducibly” measure a leak rate/fit factor of only 100 on air-purifying respirators. “The value reflects the limitations of this test method,” he said.

Provision 1910.134(f)(7) states that a respirator will pass a quantitative fit test if the fit factor is 100 or greater for half facepieces, and 500 or greater for full facepieces.

The fit factor is 10 times more than the assigned protection factor, so an assigned protection factor of 10 is equal to a fit factor of 100. Therefore, a qualitative test is only good for respirators with an assigned protection factor of 10 or less.

“A well-meaning, but uneducated, employer might do a qualitative fit test on a full facepiece and say, ‘I have an assigned protection factor of 50.’ It can only be assigned a 10 because the qualitative fit test can only measure up to [a fit factor of 100], not 500,” Johnson said.

So, qualitative testing is typically used for half-facepiece respirators, while quantitative testing can be used for both half- and full-facepiece respirators.

In an email to S+H, Maryann D’Alessandro, director of NIOSH’s National Personal Protective Technology Laboratory, and Christopher Coffey, the lab’s associate director for science, highlighted advice from the “NIOSH Guide to Industrial Respiratory Protection,” which recommends quantitative testing “when facepiece leakage must be minimized for work in highly toxic atmospheres or those immediately dangerous to life or health.”

According to the guide, one advantage of quantitative testing is not having to rely on the wearer’s subjective response. Such tests, however, require more expensive equipment and more training for test administrators compared with qualitative tests.

“Employers need to consider the limitations of each fit test method and the conditions at the workplace where respirators are required in selecting which fit test method to use,” D’Alessandro and Coffey wrote.

More details about each type of quantitative and qualitative test are available in Appendix A of 1910.134.

Other considerations

Other personal protective equipment and hair: If a worker needs to wear glasses, hearing protection or other items on the job in addition to a respirator, he or she must wear the item(s) during the fit test, as well. Certain kinds of facial hair can interfere with the respirator seal and are not allowed. Long hair might also affect the integrity of the seal.

Time: Experts said fit tests can take around 15 to 20 minutes, not including the time needed to don and adjust the respirator, or perhaps try different types of respirators to find the proper fit. OSHA requires that a respirator be worn for at least five minutes before starting a fit test “to assess comfort.”

Regardless of the testing protocol used, Janssen cautioned that the process requires more time off the job than simply performing the test exercises. For example, initial or refresher training is often combined with fit testing.

Changing respirators: Whatever size, make, model and style of respirator that a worker wears for the fit test must be the same one he or she will wear on the job. If a worker changes to a different kind of respirator, another fit test is required.

A worker’s physical change: Along with a required annual fit test, a worker will need another test if he or she experiences physical changes such as significant weight gain or loss, cosmetic surgery, major dental work or facial surgery or scarring. These changes all can affect the shape of the face and, as a result, could affect the respirator seal.

Training and qualification: No specific requirements exist for administrators of fit tests, but they have to know the procedures outlined in Appendix A. An OSHA video on fit testing states that organizations can use third parties for testing or an outside party such as a contractors association.

D’Alessandro and Coffey wrote that the voluntary ANSI/AIHA/ASSP Z88.10 standard lists “qualifications to aid the respirator protection program administrator in evaluating and verifying the training and qualification of the person(s) who perform(s) the fit test.”

How to find help

Stumped, or not quite sure where to begin your respiratory protection program and fit testing? Resources are available.

OSHA’s free On-Site Consultation Program offers confidential advice and is separate from the agency’s enforcement program. NIOSH, meanwhile, provides answers to frequently asked questions on respiratory protection.

Although not required by OSHA, formal training for leads of respiratory protection programs is desirable, said Johnson, who added that courses are available via the OSHA Training Institute Education Centers, manufacturers, and safety and health organizations.

The need to prevent or reduce the number of often debilitating and deadly ailments such as silicosis or black lung disease underscores the necessity for more effective respiratory protection, Johnson said. Part of this is ensuring tight-fitting respirators achieve the proper seal.

Respiratory protection is “presented as a simple topic when you go through the initial purchasing of a respirator,” he said. “I mean, you can get on the internet and buy one. Sometimes, the only thing you’ll get are instructions that say to follow an OSHA-approved respirator program when you use this device. But people have died or become very sick because of the basic lack of understanding of what is required to use a respirator properly.”

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