UN 3136 — Trifluoromethane, refrigerated liquid
Placard: Non-Flammable Gas. ERG Guide 120. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
Trifluoromethane, refrigerated liquid, is shipped as a cold liquefied gas. It is not flammable, but a release can create oxygen-deficient air and cryogenic contact hazards.
Hazard overview: The primary danger is asphyxiation in low or confined spaces. Cold vapor can spread along the ground at first, and liquid contact can freeze tissue quickly; heated cylinders may rupture.
Response guidance: Isolate the release, eliminate unnecessary entry and ventilate only after monitoring. Cool exposed containers from a protected position if safe, and do not enter vapor areas without SCBA.
Firefighter training notes: Train crews to treat odorless refrigerant gas releases as oxygen-deficiency incidents and to monitor before entry. Frostbite protection is required for liquid contact.
Regulatory context: UN 3136 is a Class 2 non-flammable gas entry. Shipping papers, cylinder markings and SDS should be used to confirm container type and pressure hazards.
Storage & handling: Store refrigerated containers upright, secured and protected from heat. Keep ventilation adequate and prevent cylinders from being struck or exposed to fire.
UN 3136 Quick Details
Common Hazards of UN 3136
- Non-flammable refrigerated liquefied gas; main hazards are asphyxiation, pressure and cryogenic contact.
- Cold vapor may stay low initially and displace oxygen in confined or low areas.
- Contact with liquid or cold gas can cause frostbite and cryogenic burns.
- Cylinders or insulated containers can rupture or rocket if heated.
- Fire exposure may produce toxic or corrosive decomposition products from fluorinated gas.
- The gas is colorless and odorless, so dangerous concentrations may not be noticed without monitoring.
Chemical Identity & Physical Properties
Trifluoromethane is a colorless, odorless refrigerated liquefied gas. It boils at very low temperature and can produce dense cold vapor near the release point.
| Also known as | HFC-23R-23FluoroformCHF3TrifluoromethaneRefrigerant 23Freon 23 |
| CAS Number | 75-46-7 |
| Appearance | Colorless, odorless liquefied compressed gas. Shipped as a cryogenic refrigerated liquid at extremely low temperatures. |
| Flash Point | Not applicable (non-flammable gas) |
| Boiling Point | -82C (-116F) |
| Vapor Density | 2.4 (heavier than air) |
| Water Reactivity | No significant reaction with water |
Fireground Response Guidance — UN 3136
Extinguishing Media
PPE Requirements
Use SCBA where oxygen deficiency is possible. Wear insulated gloves, face protection and cryogenic splash protection for any chance of liquid contact.
Isolation & Evacuation
First Actions for a UN 3136 Incident
- Call 911 and the emergency response number shown on the shipping paper, if available.
- Keep unauthorized personnel away and establish incident command before close approach.
- Stay upwind, uphill and upstream; avoid low areas where vapors or gases may collect.
- Avoid breathing vapors, dust, mist or fire gases and avoid skin or eye contact.
- Do not touch damaged containers or spilled material without proper PPE and training.
- Ventilate confined spaces only after atmospheric monitoring and only with trained, equipped personnel.
- Use ERG guidance, SDS, shipping papers and monitoring results for final protective actions.
📋 Copy & Share Field Card
UN 3136 — Trifluoromethane, refrigerated liquidUse 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.