Qualitative Face Fit Testing relies on the person’s sense of taste (i.e. taste response) to determine the mask’s effectiveness. Essentially, this testing uses an individual’s own perception, often via taste (hence the “taste method”) to determine whether a mask fits correctly. Specifically, the tester is looking to detect face seal through a strong tasting challenge agent, i.e. bitter or sweet.
Process
The process of Qualitative Face Fit Testing is relatively simple and straightforward. This often begins with the subject being tested wearing a polypropylene hood with a clear PVC panel. The hood is worn without the mask. Typically the tester will then spray a strong tasting solution into the hood and request that the individual indicate when they have sensed/tasted the solution. This process simply determines the quantity of solution, which will be required during the administration of the test.
Next, the subject being testing will be required to place on the mask to be tested along with the polypropylene hood. Lastly, the individual will carry out a few light and basic tasks in order to create a variety of movements. The purpose of this exercise is to simulate typical working conditions. If the subject can taste the solution during this process the tester then determine that the seal of the mask is not effective or acceptable.
Facts
Qualitative Face Fit tests require the same seven-test exercise protocol as other methods described in INDG 479, but can only be employed for fit testing of filtering facepieces (disposable masks) and half masks, not full face masks. This method involves both a ‘Sensitivity Test’ and ‘Fit Test’ step, which must both be conducted with the same test agent.