The mask fit testing protects the user from potential external hazards. What if a mask doesn’t meet the necessary requirements? What if it doesn’t fit properly on the face?
Respiratory protection masks must adhere well to the wearer’s face to provide the right protection.
A good fit ensures that the respirator adheres to the skin. Respiratory protection masks can only work when air passes through the filter.
Therefore, in many countries, the mask Fit Test is required before a user can wear a mandatory respirator at work. Also, Fit Tests must be performed:
- If you change the brand of your mask.
- If your face changes, for example, if you have changed weight significantly.
- With frequency. In the USA, the Fit Test must be repeated at least once a year.
To be sure to perform a Fit Test for your mask, you need to rely on certified operators. They must have the appropriate skills to carry out the tests, teach you how to wear respirators correctly, and how to clean the masks.
Mask fit testing: qualitative and quantitative
These tests are used to see how well the mask fits during the usual actions that a person performs during the day.
The test consists of several exercises that an operator must do with the mask under examination. As breathing normally, deeply, turning the head from one side to the other, reading and talking.
A qualitative Fit Test (QLFT) can only be used for filter facials and half masks. These quality tests may be suitable for complete masks according to specific Fit Test standards and only under certain circumstances.
A quantitative Fit Test (QNFT) can be used for any adherent respirator. It involves the use of a specific instrument to measure any air leakage.
This instrument gives a numerical value called the Fit Factor.
The tests use the same exercises as the QLFT tests. In the United States, there is also an additional “grimace” test in which the subject smiles or frowns for 15 seconds.
Mask fit testing: a test to be done
Employees wearing tight-fitting respiratory protective masks should perform a tightness test each time they wear the respirator.
If you have doubts if your mask works well, and you want to do Fit Testing, but you’re not sure to do it this way:
Block the exhalation valve on a half or full face mask respirator, or cover the surface of the respirator on a filtering face mask, usually with your hands, trying to breathe. If pressure is created, it means that there is no air leakage along the edges of the respirator.
If air comes out, ask for a Fit Test for your mask immediately.