UN 3256 — Elevated temperature liquid, flammable, n.o.s., with flash point above 37.8°C (100°F), at or above its flash point
Placard: Flammable. ERG Guide 128. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 3256 Elevated temperature liquid, flammable, n.o.s., with flash point above 37.8°C (100°F), at or above its flash point is assigned to ERG Guide 128 for initial emergency response. 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. Verify the exact product from shipping papers and SDS before selecting tactics.
Hazard overview: Primary hazards: a flammable hazardous material; vapors may form explosive mixtures and flash back. HIGHLY FLAMMABLE: Will be easily ignited by heat, sparks or flames. Vapors may form explosive mixtures with air.
Response guidance: For a UN 3256 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 128 and local incident command procedures.
UN 3256 Quick Details
Common Hazards of UN 3256
- 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 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
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.
| 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 |
Fireground Response Guidance — UN 3256
Extinguishing Media
PPE Requirements
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 & Evacuation
First Actions for a UN 3256 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.
- 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 3256 — Elevated temperature liquid, flammable,Use 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.