UN 3220 — Refrigerant gas R-125
Placard: Non-Flammable Gas. ERG Guide 126. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
Refrigerant gas R-125 is a liquefied compressed gas. It is not readily flammable, but it presents asphyxiation, frostbite and pressure hazards.
Hazard overview: The main hazards are oxygen displacement, cold liquid contact and cylinder rupture under heat. Fire may decompose the gas into toxic or corrosive products.
Response guidance: Isolate the leak, ventilate low areas if safe and cool fire-exposed containers with unmanned streams. Stop the leak only if it can be done safely.
Firefighter training notes: Train crews on cylinder pressure hazards, asphyxiation monitoring, cold-vapor behavior and the need for ventilation before entry.
Regulatory context: Compressed or refrigerated gas shipments require cylinder integrity control, pressure hazard awareness and compliance with DOT gas packaging and labeling rules.
Storage & handling: Store cylinders or refrigerated containers secured, ventilated and away from heat. Protect valves and relief devices from impact and fire exposure.
UN 3220 Quick Details
Common Hazards of UN 3220
- Non-flammable liquefied gas can displace oxygen and cause asphyxiation without warning.
- Vapors are heavier than air and may collect in low or confined areas.
- Contact with liquefied gas can cause frostbite or cold burns.
- Cylinders or containers may rupture or rocket when heated.
- Fire exposure may produce toxic and corrosive decomposition products.
- Leaks are difficult to detect by odor; use monitoring and ventilation.
Chemical Identity & Physical Properties
Colorless, odorless liquefied gas. Shipped as liquefied compressed gas under its own vapor pressure. Nonflammable under most conditions.
| Also known as | PentafluoroethaneHFC-125R-1251,1,1,2,2-PentafluoroethaneGenetron 125Suva 125 |
| CAS Number | 354-33-6 |
| Appearance | Colorless, odorless liquefied gas. Shipped as liquefied compressed gas under its own vapor pressure. Nonflammable under most conditions. |
| Flash Point | Not applicable (nonflammable gas) |
| Boiling Point | -48C (-55F) |
| Vapor Density | 4.2 (heavier than air) |
| Water Reactivity | No significant reaction; low water solubility |
Fireground Response Guidance — UN 3220
Extinguishing Media
PPE Requirements
Use SCBA in confined spaces or high concentrations, thermal gloves for cold liquid/cylinder contact and standard protective clothing for cylinder hazards.
Isolation & Evacuation
First Actions for a UN 3220 Incident
- Call 911 and the emergency response number 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, smoke or decomposition products and avoid skin or eye contact.
- Do not touch damaged containers or spilled material without appropriate PPE and monitoring.
- Ventilate confined spaces only if trained, equipped and authorized by incident command.
- Use ERG, SDS, shipping papers and atmospheric/radiation monitoring for final isolation and control decisions.
📋 Copy & Share Field Card
UN 3220 — Refrigerant gas R-125Use 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.