UN 3252 — Refrigerant gas R-32
Placard: Flammable Gas. ERG Guide 115. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 3252 At a Glance
UN 3252 (Refrigerant gas R-32) is listed as DOT Class 2 Flammable Gas and is assigned to ERG Guide 115. Use this page to review placard data, common hazards, PPE notes, isolation context, first actions, and related UN numbers.
UN 3252 Refrigerant gas R-32 is assigned to ERG Guide 115 for initial emergency response. Colorless, odorless gas at room temperature. Shipped as a liquefied compressed gas under pressure. Verify the exact product from shipping papers and SDS before selecting tactics.
Hazard overview: Primary hazards: an extremely flammable gas; vapors may form explosive mixtures and cylinders may rocket if heated. EXTREMELY FLAMMABLE. Will be easily ignited by heat, sparks or flames.
Response guidance: For a UN 3252 incident, isolate the area, keep unauthorized personnel away, stay upwind/uphill and confirm the exact material from shipping papers and SDS. Eliminate ignition sources and use the listed extinguishing media; for burning gas, do not extinguish unless the leak can be stopped. Follow ERG Guide 115 and local incident command procedures.
UN 3252 Quick Details
Common Hazards of UN 3252
- EXTREMELY FLAMMABLE.
- Will be easily ignited by heat, sparks or flames.
- Will form explosive mixtures with air.
- Vapors from liquefied gas are initially heavier than air and spread along ground.
- Vapors may travel to source of ignition and flash back.
- Cylinders exposed to fire may vent and release flammable gas through pressure relief devices.
- Containers may explode when heated.
- Ruptured cylinders may rocket.
Chemical Identity & Physical Properties
Colorless, odorless gas at room temperature. Shipped as a liquefied compressed gas under pressure.
| Also known as | DifluoromethaneHFC-32Methylene fluorideR-32CH2F2 |
| CAS Number | 75-10-5 |
| Appearance | Colorless, odorless gas at room temperature. Shipped as a liquefied compressed gas under pressure. |
| Flash Point | Not applicable (gas) |
| Boiling Point | -51.7C (-61F) |
| Vapor Density | 1.8 (heavier than air) |
| Water Reactivity | No significant reaction with water |
Fireground Response Guidance — UN 3252
Extinguishing Media
PPE Requirements
Level B minimum; SCBA required; cold-resistant gloves for handling liquefied gas to prevent frostbite
Isolation & Evacuation
First Actions for a UN 3252 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.
- Many gases are heavier than air and will spread along the ground and collect in low or confined areas.
- Isolate spill or leak area for at least 100 meters (330 feet) in all directions.
- Consider initial downwind evacuation for at least 800 meters (1/2 mile).
📋 Copy & Share Field Card
UN 3252 — Refrigerant gas R-32Use 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.