Hot flammable liquid un3256 visual test exception sign test pass apps check
UN 3256 is an elevated-temperature liquid that is also flammable. It takes the red Class 3 flammable placard, and because it travels hot, it also carries the HOT elevated-temperature marking. So you see two things: the red flammable diamond for the fire hazard, plus the HOT mark for the heat hazard. Verify the details in the regulations.
What UN 3256 is
UN 3256 is the entry for an elevated-temperature liquid, flammable, not otherwise specified. In plain terms, it is a flammable liquid that is transported hot, at or above a high temperature. That combination means it carries two hazards at once: it can burn, and it is dangerously hot.
Two hazards, two cues
Because it has two hazards, it shows two things. The fire hazard gets the standard red Class 3 flammable placard, with the flame symbol and a 3. The heat hazard gets the HOT marking, the word HOT in an upward triangle, which flags an elevated-temperature material. Neither one alone tells the whole story.
How it is marked
The pairing to remember:
| Hazard | Shown by |
|---|---|
| Flammable | Red Class 3 placard (flame, 3) |
| Hot | HOT marking (word HOT in a triangle) |
| UN number | 3256 |
| What it is | Elevated-temperature flammable liquid |
Red flammable placard plus the HOT mark. Confirm the thresholds and rules in the regulations.
Why the heat matters
A liquid carried near or above its flash point, or simply very hot, adds burn and reaction risks on top of flammability. Hot asphalt-type loads and similar materials behave differently from a cool flammable liquid, so responders need the HOT cue to handle them safely. That is why the elevated-temperature marking is added rather than relying on the flammable placard alone.
Exceptions and verifying
There are specific definitions for what counts as an elevated-temperature liquid and provisions that can apply, so not every hot load is treated identically. Because those temperature thresholds and any exceptions are detailed and can change, confirm the current requirements for UN 3256 and elevated-temperature materials in the regulations and your official manual.
Frequently asked questions
- What placard does UN 3256 use?
- The red Class 3 flammable placard for the fire hazard, plus the HOT elevated-temperature marking because it travels hot. Two cues for two hazards. Confirm in the regulations.
- What is UN 3256?
- An elevated-temperature liquid that is flammable, not otherwise specified, meaning a flammable liquid transported at high temperature, carrying both a fire and a heat hazard.
- Why does a flammable liquid also get the HOT mark?
- Because it is carried hot. The red placard shows the fire hazard and the HOT marking shows the elevated temperature, so responders see both dangers.