Respirator Fit Test
For the offensive job classifications, a respirator fit test is required. 29 CFR 1910.134 requires this test. This involves either a qualitative or quantitative fit test followed by a positive and negative pressure fitting of the respirator before engaging in cleanup of hazardous substances. A qualitative fit test is a pass/fail test that relies on an individual's response to a test agent. The quantitative fit test provides a more accurate fit test. The particle concentration outside the respirator is measured against the concentration inside the respirator. The ratio of these two numbers is the fit factor.
If a person is wearing either a half-mask of full-face respirator, a person must perform a positive and negative pressure check of the seal between the face and rubber of the respirator. The negative pressure check is accomplished by placing the palms of both hands on the canister openings of the respirator and inhaling. A person should hold the exhaling pressure for 10-15 seconds and should notice a slight inward bulge of the facepiece.
The positive pressure check is done by placing the palm of one hand over the respirator exhaust valve and exhaling. A person should hold the exhaling pressure for 10-15 seconds and should notice a slight outward bulge of the facepiece.