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respiratorcalc

Respirator selection

Formaldehyde respirator selectionHCHO (CH2O)

Resins/adhesives, particleboard & plywood, embalming/pathology, textiles, disinfectants; wood-products and healthcare industries.

OSHA PEL
0.75 ppm
TWA 8-hr (29 CFR 1910.1048; also STEL 2 ppm, action level 0.5 ppm)
NIOSH REL
0.02 ppm
TWA (carcinogen, Ca; also 15-min Ceiling 0.1 ppm)
IDLH
20 ppm
Molecular weight
30.03 g/mol

Calculator for Formaldehyde

Inputs

Formaldehyde exposure

Unit
ppm
ppm
ppm

Enter molecular weight to convert values when you switch between ppm and mg/m³.

Result

Enter a concentration and an exposure limit to see the compliant respirators and their Maximum Use Concentration.

Hazard ratio = concentration ÷ OEL · Minimum APF must meet or exceed it · MUC = APF × OEL (capped at IDLH). Source: OSHA 29 CFR 1910.134(d)(3)(i)(A), Table 1 — Assigned Protection Factors. Last verified 2026-07-16.

Maximum use concentration for Formaldehyde by respirator

MUC = APF × the OSHA PEL (0.75 ppm), capped at the IDLH (20 ppm). Use this as a reference for the highest concentration each respirator class may be used at.

RespiratorAPFMUC (ppm)
Air-Purifying Respirator · Quarter mask53.75
Air-Purifying Respirator · Half mask107.5
Supplied-Air Respirator (Airline) · Half mask · Demand107.5
Self-Contained Breathing Apparatus · Half mask · Demand107.5
Powered Air-Purifying Respirator · Helmet / hood2518.75
Powered Air-Purifying Respirator · Loose-fitting facepiece2518.75
Supplied-Air Respirator (Airline) · Helmet / hood · Continuous flow2518.75
Supplied-Air Respirator (Airline) · Loose-fitting facepiece · Continuous flow2518.75
Air-Purifying Respirator · Full facepiece5020IDLH
Powered Air-Purifying Respirator · Half mask5020IDLH
Supplied-Air Respirator (Airline) · Full facepiece · Demand5020IDLH
Supplied-Air Respirator (Airline) · Half mask · Continuous flow5020IDLH
Supplied-Air Respirator (Airline) · Half mask · Pressure-demand / positive-pressure5020IDLH
Self-Contained Breathing Apparatus · Full facepiece · Demand5020IDLH
Powered Air-Purifying Respirator · Full facepiece1,00020IDLH
Supplied-Air Respirator (Airline) · Full facepiece · Continuous flow1,00020IDLH
Supplied-Air Respirator (Airline) · Full facepiece · Pressure-demand / positive-pressure1,00020IDLH
Self-Contained Breathing Apparatus · Full facepiece · Pressure-demand / positive-pressure10,00020IDLH

Notes

Verified via NIOSH IDLH page + NPG search data (live NPG card fetch was 403 — re-verify card directly). OSHA 1910.1048: TWA 0.75 ppm, STEL 2 ppm, action level 0.5 ppm. NIOSH REL Ca: TWA 0.016 ppm with 15-min Ceiling 0.1 ppm. IDLH Ca [20 ppm]. Conversion 1 ppm = 1.23 mg/m3; MW 30.0.

Sources

Data confidence: high. Values are cited from OSHA and NIOSH but should be verified against the current source and a qualified professional before use. See how this works.

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