UN 1952 — Ethylene oxide and carbon dioxide mixture, with not more than 9% ethylene oxide
Placard: Non-Flammable Gas. ERG Guide 126. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 1952 is Ethylene oxide and carbon dioxide mixture, with not more than 9% ethylene oxide, a compressed gas mixture assigned to ERG Guide 126. Although diluted with carbon dioxide, the ethylene oxide component creates toxic exposure concerns.
Hazard overview: UN 1952 presents inhalation toxicity, pressure/container rupture, low-area vapor and toxic fire-product hazards.
Response guidance: For a UN 1952 incident, verify the product with shipping papers, container markings, SDS and ERG Guide 126. Establish incident command, isolate the area, stay upwind, control ignition or downwind hazards, cool exposed containers from a protected distance when appropriate and base entry decisions on monitoring and local SOP.
Firefighter training notes: Training for UN 1952 should emphasize pressure/fire hazards, exposure routes, air monitoring, PPE selection, evacuation and ERG/SDS verification. Use ERG 126, SDS and local SOP.
Regulatory context: Ethylene oxide and carbon dioxide mixture, with not more than 9% ethylene oxide is regulated as a hazardous material for transportation and emergency response purposes. Requirements for storage, workplace exposure, emergency planning, spill reporting and waste handling vary by exact product, concentration, quantity and jurisdiction. Verify current requirements through shipping papers, SDS, container markings and applicable DOT, OSHA, EPA, NFPA, state or local authority guidance.
Storage & handling: Ethylene oxide and carbon dioxide mixture, with not more than 9% ethylene oxide should be stored in compatible containers in a secure, cool, ventilated hazardous-material area according to SDS and local procedures.
UN 1952 Quick Details
Common Hazards of UN 1952
- COMPRESSED GAS MIXTURE containing ethylene oxide; may be toxic, irritating and carcinogenic even when diluted with carbon dioxide.
- Containers may rupture or rocket when heated.
- Vapors may displace oxygen and collect in low or confined areas.
- Ethylene oxide component may burn under certain conditions and can produce toxic combustion products.
- Contact with liquefied gas may cause frostbite or cold burns.
- Fire may produce irritating, corrosive and/or toxic gases.
- Leaking gas should be treated as an inhalation and exposure-control incident.
Chemical Identity & Physical Properties
Colorless, compressed gas mixture with a sweet, ether-like odor from the ethylene oxide component. Shipped as a liquefied gas under pressure in cylinders.
| Also known as | ETO/CO2 mixtureEthylene oxide-carbon dioxide blendSterilant gas mixtureOxyfume mixtureEO/CO2 sterilizing gas |
| Appearance | Colorless, compressed gas mixture with a sweet, ether-like odor from the ethylene oxide component. Shipped as a liquefied gas under pressure in cylinders. |
| Flash Point | Not applicable (compressed gas mixture below flammable limit) |
| Boiling Point | Not applicable (multi-component gas mixture) |
| Vapor Density | 1.5 (heavier than air) |
| Water Reactivity | No significant reaction with water, though ethylene oxide is miscible |
Fireground Response Guidance — UN 1952
Extinguishing Media
PPE Requirements
Use SCBA and oxygen monitoring in confined or oxygen-deficient areas. Wear face shield, insulated or cryogenic gloves and protective clothing when liquefied or refrigerated gas contact is possible.
Isolation & Evacuation
First Actions for a UN 1952 Incident
- CALL 911. Then call the emergency response telephone number on the shipping paper, if available.
- Keep unauthorized personnel away.
- Stay upwind, uphill and/or upstream.
- Avoid breathing gas, vapor, smoke or mist and avoid skin or eye contact.
- Eliminate ignition sources if safe and keep gas or vapor out of drains, sewers, basements and low areas.
- Do not touch damaged containers or spilled/released material unless properly trained and wearing appropriate protective equipment.
- Ventilate closed spaces before entering, but only if properly trained, equipped, monitored and authorized by incident command.
- Isolate the release area and expand the perimeter for fire involvement, cylinder heating, vapor accumulation, unknown gas identity or downwind exposure.
- Use ERG Guide 126, shipping papers, SDS, air monitoring and incident command for protective actions.
📋 Copy & Share Field Card
UN 1952 — Ethylene oxide and carbon dioxide mixturUse for: Quick radio or face-to-face size-up. Short, structured, field-ready.
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief.
Use for: Quick text to command or incoming units. Fits in a single SMS.