These test kits are the best way to test the fit and seal of your respirator. The kits are appropriate for both disposable masks and half-face respirators. This test relies on the mask wearer being able to taste the flavour of a fine mist sprayed at them while wearing a respirator and is available in sweet (FT-10) and bitter (FT-30) versions.
Part 1: Sensitivity Test
First, unscrew the nebuliser labelled 'sensitivity test solution' and add a teaspoon's worth of the sensitivity test solution. Also fill the second nebuliser in the same way with the fit test solution. Put the tops back on the nebulisers and remove the cap to test that both of the nebulisers spray a fine mist.
Make sure the test subject hasn't had anything to eat or drink (besides water) and hasn't been chewing gum for at least 15 minutes before the test. If they haven't, place the hood without a respirator with an approximate 15cm gap between the front of the hood and their mouth.
Now, ask the test subject to breathe through their mouths with their tongue slightly out and to indicate when they can taste the solution. Place the nebuliser through the hole in the hood and squeeze the solution into the hood, letting the bulb fully inflate before each squeeze. Count and note the number of squeezes it takes before the wearer indicates that they can taste the solution.
If the wearer indicates tasting the solution between 1-10 squeezes, 10 squeezes should be used for the next part of the test. If they indicated between 11-20, 20 squeezes should be used; between 21-30, 30 should be used. However, if it took more than 30 squeezes, you should do the test with the other kit and retry the sensitivity test as some people cannot taste detect certain tastes.
Before taking the next part of the test, you should give the test subject time to clear the taste from their mouth. You may also ask them to rinse with water and wipe their lips to get rid of the lasting solution.
Part 2: Fit Test
When all remaining taste has been eliminated, explain to the test subject the next part of the test. Tell them you're going to ask them to perform some actions to check the fit of their mask. Explain to them you're going to, at different points in the test, ask them to breathe normally, then breathe deeply, turn their head side to side, then up and down, talk (i.e count backwards from 100), bend over (as if touching their toes) and breathe, and finally breathe normally again.
Fit the respirator on the subject and do a standard fit test. Ask them to wear any other PPE, such as goggles, that may affect the fit of their respirator.
Put the hood on as before and once again ask the wearer to breathe through their mouth with their tongue slightly out and to indicate if they can taste the solution. Place the nebuliser through the hole in the hood and squeeze the solution into the hood either 10, 20, or 30 times according to the results of the sensitivity test, letting the bulb fully inflate before each squeeze. Start the test with the exercises above, starting with breathing normally. Every 30 seconds, squeeze half of the initial number into the hood (5, 10, or 15) to maintain the concentration of solution in the hood. Periodically test that the nebuliser isn't clogged. If it is, clear it and retest.
If at any point the wearer indicates that they can taste the solution, you should stop the test, refit the respirator, and repeat the Fit Test when the taste has cleared. If the wearer indicates twice, this may mean that the mask isn't right for the test subject.
If the test is completed without the wearer indicating they could taste the solution, the mask is fitted properly.
Cleaning the Test Kit
Remove all solution from the nebulisers after every session or at least every 4 hours. Never pour the solution from the nebuliser back into the bottle, always discard safely.
Rinse the nebuliser with warm water and shake dry.
Wipe down the inside of the hood with a damp cloth or paper towel to remove any remaining solution.