How to Complete a Respirator Fit Test
Fit testing ensures a respirator is doing the job it was made for.
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Some occupations require workers to enter confined spaces, handle harsh materials, encounter large quantities of dust, or face other conditions that involve respiratory hazards. Unless they are equipped with adequate personal protective equipment (PPE) and trained in its proper use and maintenance, these workers are at risk of respiratory injury, oxygen deficiency, or occupational illnesses.
Respirators are an essential line of defense against all types of inhalation and atmospheric hazards. In order to be effective, however, these respirators must pass the fit test for every single person who needs to wear them.
Respirators protect workers by performing two basic functions:
- Removing contaminants by filtering out airborne particles, chemicals, or gases
- Supplying clean, breathable air by means of compressed air from a remote source or from a self-contained breathing apparatus (SCBA) with its own air supply
Gases, vapors, and fumes, however, can find their way into the smallest openings. Even the most sophisticated respirators, then, can't provide sufficient protection unless they are fitted so that they create an effective seal on the user's face.
Selecting the Right Respirator
Before testing the fit of a respirator, make sure that the user is outfitted with the right respirator for their job.
There are two major factors to consider when making your selection:
- The type of hazards the worker will be exposed to
- The level of protection they will require to carry out their work safely
Once you've determined this, the next step is to make sure the respirator fits well.
Before performing a formal fit test, you can run through the following checklist to quickly assess the fit:
- Does the respirator form a good seal over the nose, face, and cheeks?
- Is there adequate space for eye protection?
- Can the user speak while wearing the respirator?
- Is the chin positioned properly?
- Is the strap taught but not too tight?
- Is there a chance for the respirator to slip?
Fit Testing Procedures
There are two fit testing methods: qualitative fit testing (QLFT) and quantitative fit testing (QNFT). The following exercises are performed as part of all fit testing methods, except the CNP and CNP REDON QNFT protocols.
The user must perform these exercises while wearing any prescription eyewear or PPE (like earmuffs, hard hats, or safety glasses) they might be wearing in conjunction with their respirator.
The tests must also be performed in an appropriate test environmen. Each exercise is carried out for one minute, with the exception of the grimace test which lasts only fifteen seconds.
If the employee becomes uncomfortable or the respirator fails, another respirator should be selected and the test restarted.
- Normal breathing - In a normal standing position, without talking, the subject shall breathe normally.
- Deep breathing – In a normal standing position, the subject shall breathe slowly and deeply without hyperventilating.
- Turning the head side to side – Standing in place, the subject shall slowly turn their head from side to side, reaching the extreme position on each side. The head shall be held at each extreme momentarily so the subject can inhale at each side.
- Moving the head up and down - Standing in place, the subject shall slowly move their head up and down. The subject shall be instructed to inhale while their head is in the upward position.
- Talking – The subject shall talk, loudly enough so as to be heard clearly by the test conductor. The subject can read the Rainbow Passage, count backward from 100, or recite a memorized poem or song.
- Grimace – The test subject shall grimace by smiling or frowning.
- Bending over – The test subject shall bend at the waist as if they were trying to touch their toes.
- Normal breathing – Repeat the first exercise.
Using the Right Respirator Fit Test
As mentioned above, there are two types of respirator fit tests. The right method will be dictated by the job requirements.
Either of these types of tests are easy to carry out and can be completed in 15 to 20 minutes. Requirements for fit testing are detailed in Appendix A of OSHA's 1910.134 App A - Fit Testing Procedures (Mandatory).
Qualitative Fit Test (QLFT)
Qualitative fit tests (QLFT) and rely on the user's senses to detect the presence of a leak in the respirator facepiece. QLFTs are pass/fail, meaning they don't actually measure how much substances leaks through the facepiece, but simply that there is a leak.
This type of test is generally used for respirators that only cover the mouth and nose (half-mask respirators).
The test is performed by having the user don the respirator and then releasing one of the following substances:
- Isoamyl acetate, which smells like bananas
- Saccharin, which tastes sweet
- Bitrex, which tastes bitter
- Irritant smoke, which causes an involuntary cough reflex
If the user can detect or reacts to the substance, the fit test fails.
Quantitative Fit Test (QNFT)
Instead of relying on the user's personal judgment, quantitative fit testing (QNFT) gauges leakage with a probe and hose connected to the respirator facepiece. Unlike QLFTs, this procedure provides a numerical measurement of the amount of leakage from the ambient atmosphere into the respirator.
QNFTs can be used for any tight-fitting respirator.
OSHA lists the following acceptable options:
- Ambient aerosol condensation nuclei counter (CNC)
- Controlled negative pressure
- Generated aerosol
- Modified ambient aerosol condensation nuclei counter for full and half face-piece elastomeric respirators
- Modified ambient aerosol CNC for filtering face-piece respirators
Fit Testing Portability
For employees who transfer employment, fit tests that were conducted within the last twelve months are accepted. However, they should be for the exact make, model, style, and size of respirator that will be used on the new job.
This option is known as fit testing portability and it allows fit testing to follow workers, provided the record-keeping meets OSHA’s standards.
Factors That Affect the Seal
Respirator fit tests should be done annually unless the user undergoes a significant physical change that could affect the seal. Situations that would call for another fit test include:
- Significant weight gain or weight loss
- Major dental work
- Facial surgery
- Scarring in the vicinity of the seal
- Growing or shaving off facial hair
- New prescription eyeglasses or personal protective equipment
For all things Respiratory Protection, check out our Respiratory Protection Knowledge Center.