Reference

OSHA 1910.134(f) requires annual fit testing for all tight-fitting respirators. This guide covers 4 QLFT protocols (isoamyl acetate, saccharin, Bitrex, irritant smoke), 3 QNFT protocols (generated aerosol, PortaCount, CNP), pass/fail fit factor thresholds, the facial hair rule, recordkeeping, and a 6-step full-face APR onboarding example.

OSHA 29 CFR 1926.103 is the construction respiratory protection standard. It requires all construction employers to comply with 29 CFR 1910.134 — including written programs, medical evaluations, and fit testing. This guide covers APF selection, silica and asbestos rules, common citation triggers and a worked example for concrete grinding.

What Happens If a Respirator Doesn't Fit: A respirator that does not seal properly against the face stops working as rated. Fit failure collapses the assigned protection factor (APF) - a half-face respirator with an APF of 10 can deliver as little as 2× protection if the face seal leaks.