☣️ UN 2457 • CLASS 3
UN 2457 — 2,3-Dimethylbutane
Placard: Flammable. ERG Guide 128. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
🚒☣️
⚠️ 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 2457 Quick Details
UN 2457
Product name: 2,3-Dimethylbutane
DOT Class: 3
Placard type: Flammable
ERG Guide: 128 (check current ERG)
Initial isolation: ERG 128: Initial isolation 50m in all directions. Protective action distance 300m downwind for large spill.
Common Hazards of UN 2457
- 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 | DiisopropylBiisopropylsym-Dimethylbutane2,3-DMB |
| CAS Number | 79-29-8 |
| Appearance | Colorless liquid with a gasoline-like or petroleum odor. Volatile hydrocarbon at room temperature. |
| Flash Point | -29°C (-20°F) |
| Boiling Point | 58°C (136°F) |
| Vapor Density | 3.0 (heavier than air) |
| Water Reactivity | Insoluble in water, floats on surface. No significant reaction with water. |
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Fireground Response Guidance — UN 2457
Extinguishing Media
AFFF or alcohol-resistant foam, CO2, dry chemical, water spray for cooling
PPE Requirements
⚠️ Level B minimum with SCBA required in vapor zones. Full protective clothing for fire or leak response.
Isolation & Evacuation
ERG 128: Initial isolation 50m in all directions. Protective action distance 300m downwind for large spill.
Always confirm protective actions with the current edition of the Emergency Response Guidebook (ERG Guide 128).
First Actions for a UN 2457 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 2457 — 2,3-DimethylbutaneHAZMAT RADIO NOTE — UN 2457
Product: 2,3-Dimethylbutane
Class 3 / Flammable / ERG 128
PPE: Level B minimum with SCBA required in vapor zones. Full protective clothing for fire or leak response.
ISOLATION: ERG 128: Initial isolation 50m in all directions. Protective action distance 300m downwind for large spill.
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 2457 — 2,3-Dimethylbutane
Class: 3 | Placard: Flammable | ERG Guide: 128
Appearance: Colorless liquid with a gasoline-like or petroleum odor. Volatile hydrocarbon at room temperature.
Water Reactivity: Insoluble in water, floats on surface. No significant reaction with water.
Extinguishing: AFFF or alcohol-resistant foam, CO2, dry chemical, water spray for cooling
PPE: Level B minimum with SCBA required in vapor zones. Full protective clothing for fire or leak response.
Isolation: ERG 128: Initial isolation 50m in all directions. Protective action distance 300m downwind for large spill.
— 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/2457 | Always use current ERG + SOP/SOGIC BRIEFING
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief. Full chemical + response details.
UN2457 2,3-Dimethylbutane Cls3 ERG128 | ERG 128: Initial isolation 50m in all directions. Protective action distance 300 | allfirefighter.com/hazmat/un/2457SMS / 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/2457
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Frequently Asked Questions about UN 2457
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 required in vapor zones. Full protective clothing for fire or leak response.
Water reactivity: Insoluble in water, floats on surface. No significant reaction with water.. Recommended extinguishing: AFFF or alcohol-resistant foam, CO2, dry chemical, water spray for cooling.
ERG Guide 128 recommendation: ERG 128: Initial isolation 50m in all directions. Protective action distance 300m downwind for large spill.
No. This is a training/quick-reference aid only. Always consult the current ERG Guide 128 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.