Why get a fit test?

A respirator only works properly if it fits properly. There are specific requirements, spelled out by each province’s occupational health and safety board, that determine whether the respirator is being worn properly. While these requirements vary slightly between jurisdictions, two things they have in common are quantitative and qualitative testing.

What kind of masks require fit tests?

If your workplace requires employees to wear the following types of tight-fitting respirators, periodic fit testing is needed:

• Filtering facemasks (including N95 and KN95)
• Half-face respirators
• Full-face respirators
• SCBAs

These masks are only effective when a seal is created around the wearer’s mouth and nose. Loose-fitting respirators, on the other hand, cover the wearer’s face and head and often attach to a separate air supply. These require an entirely different kind of fit testing to make sure they work properly. In general, fit testing needs to be carried out either every two years, whenever the wearer’s physical appearance dramatically changes (through weight gain or loss, surgery, dental work, etc.), or if they wear a different model than they did before.

Qualitative fit tests

To perform a qualitative fit test, employees are placed into a special, sealed hood with an air intake valve, without their respirator on. The tester will then spray a strongly-scented solution directly into the hood through the intake valve, until the employee is able to detect it. This is known as a sensitivity test. Once sensitivity is recorded, the hood is removed and kept off until the employee doesn’t smell or taste the solution any more. The employee then wears the respirator needing testing, and the tester visually verifies its fit. Then the hood is placed back on and the solution is sprayed through the intake valve, according to the sensitivity recorded earlier. The tester will have the employee perform a number of tasks, like breathing, talking, and moving their head in a variety of directions while the solution is sprayed. If the employee can’t detect the solution despite performing these actions, the respirator is a good fit. If any of these actions allow the employee to detect the solution, more adjustments are required.

Quantitative fit tests

Quantitative fit tests are more accurate than qualitative tests, but require expensive equipment and a tester with proper experience in using it. These machines feature a screen, tubes, and ultra-sensitive internal measuring equipment. The machine also needs to be approved by your province’s occupational health and safety board in order for the test to be official. The employee begins by putting the respirator on, then the measuring machine. The employee will be asked to talk, turn their head from side to side, nod, and anything else the job might require. These actions are required and standardized by the Canadian Standards Association. During the test, the machine measures particulate levels inside the mask, compared to the ambient air outside the mask. If high levels of particles are measured inside the respirator, it’s not a good fit. If low or no levels of particles are measured inside the respirator, it’s a good fit.

Preparing employees for fit tests

For the most accurate results possible, employees must not eat, drink anything other than water, chew gum, or smoke in the 30 minutes before the test. Employees must be medically cleared to wear a respirator, and those with conditions that prevent wearing one must be accommodated in some other way. Since facial hair can interfere with a proper seal, the employee must be clean shaven in the area where the respirator seals against the face. The employee must also wear anything else required for work, such as safety goggles or PPE, during the fit testing to ensure a proper fit during normal working circumstances.

What if they fail the test?

If a worker fails the test, it means the respirator being tested is not a good fit for them and a proper seal has not been made. The first course of action is to adjust the respirator, but if this doesn’t fix the issue, a different make or model should be considered. That’s why it’s important to have alternative respirators available—not every respirator will fit every face perfectly. If an alternative cannot be found, the employee will need a proper replacement at some point in order to legally (and safely) do their job. This is your responsibility as an employer. If the worker passes the test, they will be given documentation showing they’ve been properly assessed and fitted for a specific type of respirator. This certification is good for up to two years. If changes to the employee’s physical condition affect the respirator fit, they will need to be retested.