Respirator selection
Methanol respirator selectionCH4O
Solvent, antifreeze/de-icer, fuel and fuel additive, windshield-washer fluid, and feedstock (formaldehyde, biodiesel). Chemical manufacturing.
These are federal OSHA limits. The PEL shown is the federal OSHA value. About two dozen states run their own OSHA-approved plans, and some — notably California (Cal/OSHA) — enforce lower or additional exposure limits. If you work under a state plan, check your state's PEL and enter it as a custom limit in the calculator.
⚠ Air-purifying respirators are NOT permitted
A supplied-air respirator (SAR) or SCBA is required for methanol. An APF/MUC figure does not make an air-purifying respirator acceptable here. VERIFIED against NIOSH npgd0397: the Pocket Guide lists ONLY supplied-air respirators (up to 6000 ppm) and SCBA/SAR (IDLH 6000 ppm) — no chemical-cartridge APR is listed at any concentration. Methanol has poor warning properties (odor threshold above hazardous levels) and is poorly adsorbed / rapidly broken through by activated-carbon OV cartridges. Supplied-air or SCBA is required. See the cartridge & filter guide.
⚠ Skin absorption hazard: a respirator alone is not enough
Methanol carries a NIOSH "skin" notation and is readily absorbed through the skin, so skin protection is required alongside respiratory protection. Wear chemical-protective gloves and clothing rated for this substance, plus eye and face protection. Flame-resistant (FR) clothing guards against flash fire, not chemical permeation, so it is not a substitute for a chemical-protective suit.
⚠ Skin absorption hazard: a respirator alone is not enough
Methanol carries a NIOSH "skin" notation and is readily absorbed through the skin, so skin protection is required alongside respiratory protection. Choose gloves and protective clothing rated against this chemical (check the Safety Data Sheet for permeation data), and use eye protection.
Calculator for Methanol
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.
| Respirator | APF | MUC (ppm) |
|---|---|---|
| Air-Purifying Respirator · Quarter mask | 5 | 1,000 |
| Air-Purifying Respirator · Half mask | 10 | 2,000 |
| Supplied-Air Respirator (Airline) · Half mask · Demand | 10 | 2,000 |
| Self-Contained Breathing Apparatus · Half mask · Demand | 10 | 2,000 |
| Powered Air-Purifying Respirator · Helmet / hood | 25 | 5,000 |
| Powered Air-Purifying Respirator · Loose-fitting facepiece | 25 | 5,000 |
| Supplied-Air Respirator (Airline) · Helmet / hood · Continuous flow | 25 | 5,000 |
| Supplied-Air Respirator (Airline) · Loose-fitting facepiece · Continuous flow | 25 | 5,000 |
| Air-Purifying Respirator · Full facepiece | 50 | 6,000IDLH |
| Powered Air-Purifying Respirator · Half mask | 50 | 6,000IDLH |
| Supplied-Air Respirator (Airline) · Full facepiece · Demand | 50 | 6,000IDLH |
| Supplied-Air Respirator (Airline) · Half mask · Continuous flow | 50 | 6,000IDLH |
| Supplied-Air Respirator (Airline) · Half mask · Pressure-demand / positive-pressure | 50 | 6,000IDLH |
| Self-Contained Breathing Apparatus · Full facepiece · Demand | 50 | 6,000IDLH |
| Powered Air-Purifying Respirator · Full facepiece | 1,000 | 6,000IDLH |
| Supplied-Air Respirator (Airline) · Full facepiece · Continuous flow | 1,000 | 6,000IDLH |
| Supplied-Air Respirator (Airline) · Full facepiece · Pressure-demand / positive-pressure | 1,000 | 6,000IDLH |
| Self-Contained Breathing Apparatus · Full facepiece · Pressure-demand / positive-pressure | 10,000 | 6,000IDLH |
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
- https://www.cdc.gov/niosh/npg/npgd0397.html
- https://www.cdc.gov/niosh/idlh/67561.html
- https://www.osha.gov/annotated-pels/table-z-1
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.