What is a fit test? A fit test is a test protocol conducted to verify that a respirator is both comfortable and correctly fits the user. Fit testing uses a test agent, either qualitatively detected by the wearer’s sense of taste, smell or involuntary cough (irritant smoke) or quantitatively measured by an instrument, to verify the respirator’s fit.
You must be fit tested before you use a respirator in the workplace, and you must be retested at least every 12 months as per WorkSafeBC Regulation 8.40 to make sure that the respirator you use still fits you. You must be fit tested with the specific make, model, style, and size of respirator that you will be using.
A fit test should not be confused with a user seal check. A user seal check is a quick check performed by the wearer each time the respirator is put on. It determines if the respirator is properly seated to the face or needs to be readjusted.
There are two types of fit tests: qualitative and quantitative.
Qualitative fit testing is a pass/fail test method that uses your sense of taste or smell with your reaction to an irritant in order to detect leakage into the respirator facepiece. Whether the respirator passes or fails the test is based simply on you detecting leakage of the test substance into your facepiece.
Qualitative fit testing is normally used for half-mask respirators - those that just cover your mouth and nose.
There are four qualitative fit test irritants:
- Bitrex, which leaves a bitter taste in your mouth (most commonly used)
- Isoamyl acetate, which smells like bananas
- Saccharin, which leaves a sweet taste in your mouth, and
- Irritant smoke, which can cause coughing
Qualitative fit testing determines whether or not your employees can detect various scents and flavors or can experience a negative reaction to a substance that can cause burning or watering of the eyes.
Quantitative fit testing uses a PortaCount to measure the actual amount of leakage into the facepiece and does not rely upon your sense of taste, smell, or irritation in order to detect leakage. The respirators used during this type of fit testing will have a probe attached to the facepiece that will be connected to the PortaCount by a hose.
Quantitative fit testing can be used for any type of tight-fitting respirator.
There are three quantitative fit test methods:
- Generated aerosol
- Ambient aerosol
- Controlled negative pressure
At the conclusion of the testing each employee will receive a wallet size certificate. Employers will be emailed a certificate for their employee files.