Respirator selection
Ethylene oxide respirator selectionC2H4O
Sterilization of heat-sensitive medical devices, fumigant, and chemical intermediate (ethylene glycol, surfactants); healthcare and chemical industries.
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.
Cartridge (limited use): Full-facepiece gas-mask canister approved for ethylene oxide (very limited)
An APR fitted with the correct cartridge is only adequate up to its MUC (below) — the cartridge must be able to capture ethylene oxide. VERIFIED against NIOSH npgd0275: the Pocket Guide permits an air-purifying FULL-facepiece gas mask with a chin/front/back-mounted EtO-approved canister only up to 5 ppm (APF 50) and for escape; SCBA or supplied-air-with-auxiliary-SCBA is required above 5 ppm and at IDLH (800 ppm). Governed by OSHA 1910.1047. EtO has very poor warning properties (odor threshold hundreds of ppm vs a 1 ppm PEL) and is poorly adsorbed — ordinary OV cartridges are NOT adequate and supplied air/SCBA is strongly preferred for any sustained work. You must establish a change-out schedule; never rely on taste or smell. See the cartridge & filter guide.
Calculator for Ethylene oxide
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 Ethylene oxide by respirator
MUC = APF × the OSHA PEL (1 ppm), capped at the IDLH (800 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 | 5 |
| Air-Purifying Respirator · Half mask | 10 | 10 |
| Supplied-Air Respirator (Airline) · Half mask · Demand | 10 | 10 |
| Self-Contained Breathing Apparatus · Half mask · Demand | 10 | 10 |
| Powered Air-Purifying Respirator · Helmet / hood | 25 | 25 |
| Powered Air-Purifying Respirator · Loose-fitting facepiece | 25 | 25 |
| Supplied-Air Respirator (Airline) · Helmet / hood · Continuous flow | 25 | 25 |
| Supplied-Air Respirator (Airline) · Loose-fitting facepiece · Continuous flow | 25 | 25 |
| Air-Purifying Respirator · Full facepiece | 50 | 50 |
| Powered Air-Purifying Respirator · Half mask | 50 | 50 |
| Supplied-Air Respirator (Airline) · Full facepiece · Demand | 50 | 50 |
| Supplied-Air Respirator (Airline) · Half mask · Continuous flow | 50 | 50 |
| Supplied-Air Respirator (Airline) · Half mask · Pressure-demand / positive-pressure | 50 | 50 |
| Self-Contained Breathing Apparatus · Full facepiece · Demand | 50 | 50 |
| Powered Air-Purifying Respirator · Full facepiece | 1,000 | 800IDLH |
| Supplied-Air Respirator (Airline) · Full facepiece · Continuous flow | 1,000 | 800IDLH |
| Supplied-Air Respirator (Airline) · Full facepiece · Pressure-demand / positive-pressure | 1,000 | 800IDLH |
| Self-Contained Breathing Apparatus · Full facepiece · Pressure-demand / positive-pressure | 10,000 | 800IDLH |
Notes
OSHA 1910.1047: TWA 1 ppm plus 5 ppm 15-min Excursion Limit. NIOSH REL Ca: TWA <0.1 ppm (0.18 mg/m3) with 5 ppm Ceiling [10-min/day]. IDLH Ca [800 ppm]. Conversion 1 ppm = 1.80 mg/m3; MW 44.1.
Sources
- https://www.cdc.gov/niosh/npg/npgd0275.html
- https://www.cdc.gov/niosh/idlh/75218.html
- https://www.osha.gov/annotated-pels/table-z-1
- https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1047
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.