A respirator must be fit-tested before it is used for protection against an actual airborne hazard.
Fit-testing ensures an adequate seal between the user’s face and the material of the respirator.
The fit test method can be quantitative or qualitative.
The Quantitative Fit Test (QNFT) uses an instrument that measures either leakage of an aerosol test agent or face piece pressure loss.
Qualitative Fit Testing (QLFT) is performed using odor, taste or irritation response.
Odor testing is done using banana oil (isoamyl acetate).
Taste testing uses saccharin or Bitrextm (denatonium benzoate).
Irritating smoke (stannic chloride) is used as an irritant to test a respirator’s seal.