Fit testing for respirators
As an employer, you must make sure each worker who needs a tight-fitting respirator is fit tested. A fit test checks that a tight-fitting respirator seals properly to a worker’s face. You must not issue a worker a tight-fitting respirator until a fit test shows it forms an effective seal.
Loose-fitting respirators, like hoods and helmets, don’t need a fit test.
For an overview of fit testing methods and a sample fit test form, consult Breathe Safer: How to Use Respirators Safely and Start a Respirator Program.
Knowledge required
- Which respirators you’ve chosen for the work
- Which workers will wear tight-fitting respirators
- CSA Standard Z94.4-18, which sets out how fit tests must be done
What you need
- A trained fit tester
- Several sizes and models of the respirators you’ve chosen
- Fit test equipment and a test agent, or a fit test machine
- The other personal protective equipment (PPE) each worker will wear with the respirator
- A way to record results
When fit testing is required
Workers must be fit tested:
- Before they use a tight-fitting respirator for the first time
- At least once a year
- When they change to a different facepiece, such as a different:
- Brand
- Model
- Size
- When their physical condition changes in a way that could affect the fit, including:
- Large weight gain or loss
- New dentures
- Facial surgery
- A facial injury
A fit test is for one specific make, model, and size. If a worker uses more than one tight-fitting respirator, they need a fit test for each one.
Who can do fit testing
The person who does the fit test must be trained following CSA Standard Z94.4-18. They can be:
- Someone at your workplace who’s been properly trained
- An occupational health and safety consultant or safety supply company representative from an outside fit testing service
Find out how to access CSA standards.
Prepare for a fit test
-
1
Check for medical concerns first.
If there’s any doubt that a worker can safely wear a respirator, get them medically assessed before the fit test. Refer to Get workers medically assessed to wear a respirator.
-
2
Have several sizes and models ready.
Workers should be able to choose the one that’s most comfortable, and that they’d wear most consistently.
-
3
Tell the worker how to prepare.
Before the day of the test, let them know:
- Facial hair, jewellery, clothing, or anything else that comes between their skin and the respirator’s seal will affect the results. For many workers with facial hair, this means shaving where the respirator seals against the face within 24 hours before the test, and preferably within 12 hours.
- They must wear any other PPE they’ll use with the respirator that could affect the fit, such as:
- Safety eyewear
- Hearing protection
- A hard hat
- If they're having a qualitative fit test, they can’t smoke, chew gum, or eat or drink anything but plain water for 15 minutes before.
What happens during a fit test
The fit test follows the procedure in CSA Standard Z94.4-18. In general, the worker:
- Does a comfort check. The worker wears the respirator for at least five minutes. The fit tester checks:
- How it fits
- How tight the straps are
- Whether it stays in place when the worker moves their head and talks
- Does a user seal check. The worker must pass a user seal check before the fit test. Refer to How to do a user seal check.
- Does the fit test. The worker does a set of exercises where they:
- Breathe normally and deeply
- Turn their head
- Nod
- Talk
- Bend over
Meanwhile, the fit tester checks for leaks in one of two ways:
- Qualitative test: The worker is exposed to a test agent with a strong taste or smell, or one that causes irritation. If they can detect it, the respirator is leaking.
- Quantitative test: An instrument measures how much air leaks into the respirator.
After a fit test
- If the respirator passes, issue the worker that exact make, model, and size. The result applies only to that respirator.
- If the respirator fails, the worker may be able to adjust it and test again. If it still fails, try a different size, make, or model. Don’t issue a respirator that hasn’t passed.
- If no tight-fitting respirator passes, a loose-fitting respirator may work if it gives enough protection. Refer to Choose a respirator.
You can then:
- Record the results. You must keep a record of each worker’s fit test. Breathe Safer lists the minimum information to record and includes a sample fit test form.
- Remind workers to do a user seal check every time they put on their respirator.
Related resources
Breathe Safer: How to Use Respirators Safely and Start a Respirator Program
This book provides information on how to use respirators to protect workers from breathing hazards. Written for employers, supervisors, and workers, the book covers:
- Types of breathing...
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Please note: The content on this page is intended to help you understand and meet the requirements of the Occupational Health and Safety Regulation. More detailed information can be found in the OHS Guidelines and/or OHS Regulation.