☣️ UN 1261 • CLASS 3
UN 1261 — Nitromethane
Placard: Flammable. ERG Guide 129. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
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⚠️ 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.
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UN 1261 Quick Details
UN 1261
Product name: Nitromethane
DOT Class: 3
Placard type: Flammable
ERG Guide: 129 (check current ERG)
Initial isolation: ERG 129: Small spill isolate 30m all directions; large spill isolate 100m all directions and evacuate 800m downwind if tank/rail car involved in fire
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
| 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 |
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Fireground Response Guidance — UN 1261
Extinguishing Media
Alcohol-resistant foam, CO2, dry chemical, water spray
PPE Requirements
⚠️ Level B minimum with SCBA; chemical-resistant gloves and suit recommended due to skin absorption potential
Isolation & Evacuation
ERG 129: Small spill isolate 30m all directions; large spill isolate 100m all directions and evacuate 800m downwind if tank/rail car involved in fire
Always confirm protective actions with the current edition of the Emergency Response Guidebook (ERG Guide 129).
First Actions for a UN 1261 Incident
- CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper
- 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).
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📋 Copy & Share Field Card
UN 1261 — NitromethaneHAZMAT RADIO NOTE — UN 1261
Product: Nitromethane
Class 3 / Flammable / ERG 129
PPE: Level B minimum with SCBA; chemical-resistant gloves and suit recommended due to skin absorption potential
ISOLATION: ERG 129: Small spill isolate 30m all directions; large spill isolate 100m all directions and evacuate 800m downwind if tank/rail car involved in fire
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 1261 — Nitromethane
Class: 3 | Placard: Flammable | ERG Guide: 129
Appearance: Colorless oily liquid with a mild, fruity or disagreeable odor. Miscible with water and many organic solvents.
Water Reactivity: Miscible with water; no violent reaction under normal conditions
Extinguishing: Alcohol-resistant foam, CO2, dry chemical, water spray
PPE: Level B minimum with SCBA; chemical-resistant gloves and suit recommended due to skin absorption potential
Isolation: ERG 129: Small spill isolate 30m all directions; large spill isolate 100m all directions and evacuate 800m downwind if tank/rail car involved in fire
— Key Hazards —
• 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.
— First Actions —
• CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper
• Keep unauthorized personnel away.
• Stay upwind, uphill and/or upstream.
• Ventilate closed spaces before entering, but only if properly trained and equipped.
SOURCE: allfirefighter.com/hazmat/un/1261 | Always use current ERG + SOP/SOGIC BRIEFING
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief. Full chemical + response details.
UN1261 Nitromethane Cls3 ERG129 | ERG 129: Small spill isolate 30m all directions; large spill isolate 100m all di | allfirefighter.com/hazmat/un/1261SMS / 160 CHAR
Use for: Quick text to command or incoming units. Fits in a single SMS. Includes link to full page.
⚠️ Quick-reference only. Always use current ERG + SOP/SOG for incident-specific actions.
Page: https://allfirefighter.com/hazmat/un/1261
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Frequently Asked Questions about 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.
CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper Keep unauthorized personnel away. Stay upwind, uphill and/or upstream.
Level B minimum with SCBA; chemical-resistant gloves and suit recommended due to skin absorption potential
Water reactivity: Miscible with water; no violent reaction under normal conditions. Recommended extinguishing: Alcohol-resistant foam, CO2, dry chemical, water spray.
ERG Guide 129 recommendation: ERG 129: Small spill isolate 30m all directions; large spill isolate 100m all directions and evacuate 800m downwind if tank/rail car involved in fire
No. This is a training/quick-reference aid only. Always consult the current ERG Guide 129 and your department SOP/SOG for incident-specific protective actions.
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.