Reference

OSHA 1910.134(d)(3)(iii)(B) requires a documented change-out schedule for OV respirators. This guide covers ESLI vs. calculated schedules, 3M Service Life Software inputs, P100 replacement rules, combination OV/P100 dual service life limits, per-SKU guidance for 3M cartridges, and a 6-step worked example for solvent spray painting.

OSHA 29 CFR 1910.134 governs respiratory protection programs across general industry and construction. This guide covers every major section: written programs, APF selection, medical evaluations, fit testing, user seal checks, cartridge change-out, IDLH requirements, training, recordkeeping, and a step-by-step compliance example.

NIOSH 42 CFR Part 84 governs respirator certification in the U.S., replacing the Bureau of Mines standard in 1995. It defines the N/R/P oil-resistance classification and 95/99/100 filtration tiers. This guide covers the approval process, TC number anatomy, and step-by-step Certified Equipment List verification with a worked example.

Respirator cartridge colors follow ANSI K13.1 (required by 42 CFR 84.193): black = organic vapor, white = acid gas, magenta = P100 HEPA. This guide decodes all ten color classes, combination cartridge color bands, brand-by-brand model number mapping for 3M, Honeywell North, and Moldex, and what the colors do not tell you about a.

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.