☣️ UN 3297 • CLASS 2
UN 3297 — Ethylene oxide and chlorotetrafluoroethane mixture, with not more than 8.8% ethylene oxide
Placard: Non-Flammable Gas. ERG Guide 126. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
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⚠️ Verification required:
Broad or variable material category; verify exact product, SDS and shipping papers.
⚠️ This page is a quick-reference aid. For real incidents: stage upwind, isolate, deny entry, request Hazmat early, and consult the current ERG + SOP/SOG.
Ethylene oxide and chlorotetrafluoroethane mixture, with not more than 8.8% ethylene oxide is a compressed sterilant gas mixture containing ethylene oxide at limited concentration. It is still treated as toxic and potentially carcinogenic during leaks.
Hazard overview: Ethylene oxide mixtures may not ignite readily in this classification, but heated cylinders can rupture. Released gas can displace air and expose responders to toxic EtO vapors.
Response guidance: Isolate the cylinder or leak area, stay upwind, ventilate cautiously and protect containers from heat. Use SCBA and chemical protective clothing for leak control or rescue near the release.
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UN 3297 Quick Details
UN 3297
Product name: Ethylene oxide and chlorotetrafluoroethane mixture, with not more than 8.8% ethylene oxide
DOT Class: 2
Placard type: Non-Flammable Gas
ERG Guide: 126 (check current ERG)
Initial isolation: ERG 126: Initial isolation 100m in all directions; protective action distance 300m downwind for large spills during day; containers may explode when heated
Common Hazards of UN 3297
- Some may burn but none ignite readily.
- Containers may explode when heated.
- Ruptured cylinders may rocket.
- Vapors may cause dizziness or asphyxiation without warning, especially when in closed or confined areas.
- Vapors from liquefied gas are initially heavier than air and spread along ground.
- Contact with gas or liquefied gas may cause burns, severe injury and/or frostbite.
- Fire may produce irritating, corrosive and/or toxic gases.
Chemical Identity & Physical Properties
Colorless liquefied compressed gas mixture with a sweet, ether-like odor. Stored under pressure in cylinders at room temperature.
| Also known as | Ethylene oxide/chlorotetrafluoroethane blendEtO/CTFE mixtureEthylene oxide-R124 mixtureSterilant gas mixture |
| Appearance | Colorless liquefied compressed gas mixture with a sweet, ether-like odor. Stored under pressure in cylinders at room temperature. |
| Flash Point | Not applicable (compressed gas mixture) |
| Boiling Point | Component dependent: ethylene oxide at 10.7C (51F), chlorotetrafluoroethane at -12C (10F) |
| Vapor Density | Heavier than air (approximately 3.5-4.0 relative to air) |
| Water Reactivity | No significant reaction with water, but ethylene oxide component is slightly soluble |
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Fireground Response Guidance — UN 3297
Extinguishing Media
CO2, dry chemical, water spray for cooling containers; standard foam acceptable
PPE Requirements
⚠️ Level B minimum with SCBA required; full chemical protective clothing for spills or leaks; ethylene oxide is highly toxic and carcinogenic
Level B minimum with SCBA required; full chemical protective clothing for spills or leaks; ethylene oxide is highly toxic and carcinogenic.
Isolation & Evacuation
ERG 126: Initial isolation 100m in all directions; protective action distance 300m downwind for large spills during day; containers may explode when heated
Always confirm protective actions with the current edition of the Emergency Response Guidebook (ERG Guide 126).
First Actions for a UN 3297 Incident
- CALL 911, then contact the emergency response telephone number shown on shipping papers, if available.
- Keep unauthorized personnel away.
- Stay upwind, uphill and/or upstream.
- Many gases are heavier than air and will spread along the ground and collect in low or confined areas.
- Ventilate closed spaces before entering, but only if properly trained and equipped.
- Isolate spill or leak area for at least 100 meters (330 feet) in all directions.
- Consider initial downwind evacuation for at least 500 meters (1/3 mile).
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📋 Copy & Share Field Card
UN 3297 — Ethylene oxide and chlorotetrafluoroethaHAZMAT RADIO NOTE — UN 3297
Product: Ethylene oxide and chlorotetrafluoroethane mixture, with not more than 8.8% ethylene oxide
Class 2 / Non-Flammable Gas / ERG 126
PPE: Level B minimum with SCBA required; full chemical protective clothing for spills or leaks; ethylene oxide is highly toxic and carcinogenic
ISOLATION: ERG 126: Initial isolation 100m in all directions; protective action distance 300m downwind for large spills during day; containers may explode when heated
ACTION: Stage upwind · Isolate · Deny entry · Request HazmatRADIO
Use for: Quick radio or face-to-face size-up. Short, structured, field-ready.
=== IC HAZMAT BRIEFING ===
UN 3297 — Ethylene oxide and chlorotetrafluoroethane mixture, with not more than 8.8% ethylene oxide
Class: 2 | Placard: Non-Flammable Gas | ERG Guide: 126
Appearance: Colorless liquefied compressed gas mixture with a sweet, ether-like odor. Stored under pressure in cylinders at room temperature.
Water Reactivity: No significant reaction with water, but ethylene oxide component is slightly soluble
Extinguishing: CO2, dry chemical, water spray for cooling containers; standard foam acceptable
PPE: Level B minimum with SCBA required; full chemical protective clothing for spills or leaks; ethylene oxide is highly toxic and carcinogenic
Isolation: ERG 126: Initial isolation 100m in all directions; protective action distance 300m downwind for large spills during day; containers may explode when heated
— Key Hazards —
• Some may burn but none ignite readily.
• Containers may explode when heated.
• Ruptured cylinders may rocket.
— First Actions —
• CALL 911, then contact the emergency response telephone number shown on shipping papers, if available.
• Keep unauthorized personnel away.
• Stay upwind, uphill and/or upstream.
• Many gases are heavier than air and will spread along the ground and collect in low or confined areas.
SOURCE: allfirefighter.com/hazmat/un/ethylene-oxide-and-chlorotetrafluoroethane-un-3297 | Always use current ERG + SOP/SOGIC BRIEFING
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief.
UN3297 Ethylene oxide and chlorotetrafluoroethane mixture, with not more than 8.8% ethylene oxide Cls2 ERG126 | allfirefighter.com/hazmat/un/ethylene-oxide-and-chlorotetrafluoroethane-un-3297SMS / 160 CHAR
Use for: Quick text to command or incoming units. Fits in a single SMS.
⚠️ Quick-reference only. Always use current ERG + SOP/SOG for incident-specific actions.
Page: https://allfirefighter.com/hazmat/un/ethylene-oxide-and-chlorotetrafluoroethane-un-3297
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Frequently Asked Questions about UN 3297
UN 3297 is Ethylene oxide and chlorotetrafluoroethane mixture, with not more than 8.8% ethylene oxide, assigned to ERG Guide 126 and placarded as Non-Flammable Gas.
Yes. Ethylene oxide CTFE mixture presents a serious toxic exposure hazard; avoid inhalation, ingestion, skin contact and contaminated runoff.
Yes, corrosive effects are possible. Avoid skin and eye contact and use chemical-resistant protection.
Gas can spread downwind, collect in low or confined areas, displace oxygen or create toxic exposure depending on the material.
Use caution. No significant reaction with water, but ethylene oxide component is slightly soluble
CO2, dry chemical, water spray for cooling containers; standard foam acceptable.
Sources (high level): DOT/PHMSA marking & class concepts + ERG usage principles.
This page does not reproduce ERG guide text—always consult the current ERG for incident-specific protective actions.