Skip to content
respiratorcalc

Respirator selection

Methanol respirator selectionCH4O

Solvent, antifreeze/de-icer, fuel and fuel additive, windshield-washer fluid, and feedstock (formaldehyde, biodiesel). Chemical manufacturing.

OSHA PEL
200 ppm
TWA 8-hr (Table Z-1; 260 mg/m3)
NIOSH REL
200 ppm
TWA [skin] (also STEL 250 ppm)
IDLH
6,000 ppm
Molecular weight
32.1 g/mol

Calculator for Methanol

Inputs

Methanol 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 Methanol by respirator

MUC = APF × the OSHA PEL (200 ppm), capped at the IDLH (6,000 ppm). Use this as a reference for the highest concentration each respirator class may be used at.

RespiratorAPFMUC (ppm)
Air-Purifying Respirator · Quarter mask51,000
Air-Purifying Respirator · Half mask102,000
Supplied-Air Respirator (Airline) · Half mask · Demand102,000
Self-Contained Breathing Apparatus · Half mask · Demand102,000
Powered Air-Purifying Respirator · Helmet / hood255,000
Powered Air-Purifying Respirator · Loose-fitting facepiece255,000
Supplied-Air Respirator (Airline) · Helmet / hood · Continuous flow255,000
Supplied-Air Respirator (Airline) · Loose-fitting facepiece · Continuous flow255,000
Air-Purifying Respirator · Full facepiece506,000IDLH
Powered Air-Purifying Respirator · Half mask506,000IDLH
Supplied-Air Respirator (Airline) · Full facepiece · Demand506,000IDLH
Supplied-Air Respirator (Airline) · Half mask · Continuous flow506,000IDLH
Supplied-Air Respirator (Airline) · Half mask · Pressure-demand / positive-pressure506,000IDLH
Self-Contained Breathing Apparatus · Full facepiece · Demand506,000IDLH
Powered Air-Purifying Respirator · Full facepiece1,0006,000IDLH
Supplied-Air Respirator (Airline) · Full facepiece · Continuous flow1,0006,000IDLH
Supplied-Air Respirator (Airline) · Full facepiece · Pressure-demand / positive-pressure1,0006,000IDLH
Self-Contained Breathing Apparatus · Full facepiece · Pressure-demand / positive-pressure10,0006,000IDLH

Notes

REL TWA 200 ppm (260 mg/m3) ST 250 ppm (325 mg/m3) [skin]; PEL TWA 200 ppm; IDLH 6,000 ppm; MW 32.1; conversion 1 ppm = 1.31 mg/m3. NIOSH REL carries [skin] (dermal absorption) notation.

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.

Other substances