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 At a Glance
UN 3256 (Elevated temperature liquid, flammable, with flash point above 37.8°C…) is listed as DOT Class 3 Flammable and is assigned to ERG Guide 128. Use this page to review placard data, common hazards, PPE notes, isolation context, first actions, and related UN numbers.
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.