What does a Quantitative Fit Test Mean?
The 1998 revision to the OSHA respirator standard (1910.13) defines a Quantitative Fit Test (QNFT) as an assessment of the adequacy of respirator fit by numerically measuring the amount of leakage into the respirator. In comparison, OSHA defines a Qualitative Fit Test (QLFT) as a pass/fail fit test to assess the adequacy of respirator fit that relies on the individuals response to the test agent. OSHA accepted quantitative fit tests include generated aerosol, ambient aerosol (TSI PortaCount), and controlled negative pressure (OHD Fit Tester). OSHA accepted qualitative fit tests include isoamyl acetate, saccharin, Bitrex, and irritant smoke. When using any of these methods in the United States, be sure to follow OSHA accepted procedures and protocols since these may differ from those you may be using.
