UN 1261 — Nitromethane
Placard: Flammable. ERG Guide 129. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
Nitromethane is a highly flammable liquid used as a solvent and in the production of explosives. It is miscible with water and many organic solvents.
Hazard overview: Nitromethane is highly flammable and will be easily ignited by heat, sparks, or flames. Vapors may form explosive mixtures with air.
Response guidance: In case of a spill, isolate the area with a 30-meter radius for small spills and 100 meters for large spills. For fires, evacuate the area within an 800-meter radius if a tank or rail car is involved.
UN 1261 Quick Details
Common Hazards of UN 1261
- HIGHLY FLAMMABLE: Will be easily ignited by heat, sparks or flames.
- Vapors may form explosive mixtures with air.
- Vapors may travel to source of ignition and flash back.
- Most vapors are heavier than air. They will spread along the ground and collect in low or confined areas
- Vapor explosion hazard indoors, outdoors or in sewers.
- Those substances designated with a (P) may polymerize explosively when heated or involved in a fire.
- Runoff to sewer may create fire or explosion hazard.
- Containers may explode when heated.
Chemical Identity & Physical Properties
Nitromethane is a colorless oily liquid with a mild, fruity or disagreeable odor.
| Also known as | NitrocarbolMononitromethaneNMNitrometan |
| CAS Number | 75-52-5 |
| Appearance | Colorless oily liquid with a mild, fruity or disagreeable odor. Miscible with water and many organic solvents. |
| Flash Point | 35°C (95°F) |
| Boiling Point | 101°C (214°F) |
| Vapor Density | 2.11 (heavier than air) |
| Water Reactivity | Miscible with water; no violent reaction under normal conditions |
Fireground Response Guidance — UN 1261
Extinguishing Media
PPE Requirements
Wear Level B minimum personal protective equipment (PPE) with a self-contained breathing apparatus (SCBA), chemical-resistant gloves, and a suit due to skin absorption potential.
Isolation & Evacuation
First Actions for a UN 1261 Incident
- Keep unauthorized personnel away.
- Stay upwind, uphill and/or upstream.
- Ventilate closed spaces before entering, but only if properly trained and equipped.
- Isolate spill or leak area for at least 50 meters (150 feet) in all directions.
- Consider initial downwind evacuation for at least 300 meters (1000 feet).
📋 Copy & Share Field Card
UN 1261 — NitromethaneUse 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.