☣️ UN 3256 • CLASS 3
Elevated temperature liquid, flammable, n.o.s., with flash point above 37.8°C (100°F), at or above its flash point
Placard: Flammable. 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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Quick details
UN 3256
Class: 3
Placard type: Flammable
ERG: Guide 128 (check current ERG)
Isolation: ERG 128: Initial isolation 50m (150ft) in all directions; if tank/rail car involved in fire, isolate 800m (0.5 miles) radius and consider evacuation
Chemical & Response Details
| Also known as | Elevated temperature flammable liquid n.o.s.Hot flammable liquid n.o.s.Heated combustible liquid |
| Appearance | Generic classification for various flammable liquids transported at elevated temperatures (≥100°F/37.8°C). Physical characteristics vary depending on specific substance; typically amber to dark colored liquids with petroleum or chemical odors. |
| Flash Point | Above 37.8°C (100°F), at or above flash point during transport |
| Boiling Point | Varies by specific substance; typically 150-300°C (302-572°F) |
| Vapor Density | Typically >1 (heavier than air); varies by specific material |
| Water Reactivity | Generally no significant reaction with water, but hot liquid can cause violent boiling/spattering if water contacts it |
| Extinguishing | Alcohol-resistant AFFF foam, dry chemical, CO2; water spray for cooling only |
| PPE | ⚠️ Level B minimum required; full structural firefighters' protective clothing provides limited protection. SCBA mandatory due to toxic vapor release. Thermal protective gear recommended due to elevated temperature hazard. |
| Isolation | ERG 128: Initial isolation 50m (150ft) in all directions; if tank/rail car involved in fire, isolate 800m (0.5 miles) radius and consider evacuation |
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Common hazards (high level)
- 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.
First actions (field-minded)
- 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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UN 3256 — Elevated temperature liquid, flammable, HAZMAT RADIO NOTE — UN 3256
Product: Elevated temperature liquid, flammable, n.o.s., with flash point above 37.8°C (100°F), at or above its flash point
Class 3 / Flammable / ERG 128
PPE: Level B minimum required; full structural firefighters' protective clothing provides limited protection. SCBA mandatory due to toxic vapor release. Thermal protective gear recommended due to elevated temperature hazard.
ISOLATION: ERG 128: Initial isolation 50m (150ft) in all directions; if tank/rail car involved in fire, isolate 800m (0.5 miles) radius and consider evacuation
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 3256 — Elevated temperature liquid, flammable, n.o.s., with flash point above 37.8°C (100°F), at or above its flash point
Class: 3 | Placard: Flammable | ERG Guide: 128
Appearance: Generic classification for various flammable liquids transported at elevated temperatures (≥100°F/37.8°C). Physical characteristics vary depending on specific substance; typically amber to dark colored liquids with petroleum or chemical odors.
Water Reactivity: Generally no significant reaction with water, but hot liquid can cause violent boiling/spattering if water contacts it
Extinguishing: Alcohol-resistant AFFF foam, dry chemical, CO2; water spray for cooling only
PPE: Level B minimum required; full structural firefighters' protective clothing provides limited protection. SCBA mandatory due to toxic vapor release. Thermal protective gear recommended due to elevated temperature hazard.
Isolation: ERG 128: Initial isolation 50m (150ft) in all directions; if tank/rail car involved in fire, isolate 800m (0.5 miles) radius and consider evacuation
— 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/3256 | Always use current ERG + SOP/SOGIC BRIEFING
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief. Full chemical + response details.
UN3256 Elevated temperature liquid, flammable, n.o.s., with flash point above 37.8°C (100°F), at or above its flash point Cls3 ERG128 | allfirefighter.com/hazmat/un/3256SMS / 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/3256
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FAQ
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 required; full structural firefighters' protective clothing provides limited protection. SCBA mandatory due to toxic vapor release. Thermal protective gear recommended due to elevated temperature hazard.
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.