Reference

CSA Z94.4 is Canada's respirator standard — a selection, use, and care program built on NIOSH-certified equipment. This guide covers the 2018 edition, the two-year fit-testing cycle, provincial enforcement from WorkSafeBC to Ontario, wildfire-smoke selection against the AQHI, and a worked example for a silica-exposed BC crew.

OSHA 1910.134(e) requires medical evaluation before a worker uses a required respirator. A Physician or Licensed Health Care Professional (PLHCP) reviews the Appendix C questionnaire and issues a written determination. Covers PLHCP qualifications, questionnaire structure, determination outcomes, re-evaluation triggers, and record rules.

ANSI/ASSP Z88.2 is the consensus respiratory protection program standard, providing guidance that goes beyond OSHA 1910.134 minimums. It covers hazard identification, respirator selection, written programs, fit testing, and program evaluation. This guide explains Z88.2's structure and how it relates to 1910.134 and NIOSH 42 CFR Part 84.

OSHA requires a respirator under 29 CFR 1910.134 when engineering controls can't keep airborne exposure below the PEL, when a substance-specific standard mandates it, or in IDLH and emergency atmospheres. This guide covers the PEL trigger, required vs voluntary use, the written program, fit testing, APF selection, and a worked example.