UNunnums
2478

UN 2478Isocyanates, flammable, toxic, n.o.s. or Isocyanate solutions, flammable, toxic, n.o.s. flashpoint less than 23° C

Class 3

Flammable liquids

Summary

UN 2478 is the UN number for isocyanates, flammable, toxic, n.o.s. or Isocyanate solutions, flammable, toxic, n.o.s. flashpoint less than 23° C. It is classed in Class 3 (flammable liquids) for transport. Packing group II or III, depending on the form. Emergency responders use ERG guide 155.

Emergency response

The Emergency Response Guidebook (ERG2024) guide for this number:

  • Guide155Isocyanate solution, flammable, poisonous, n.o.s.Isocyanate solution, flammable, toxic, n.o.s.Isocyanates, flammable, poisonous, n.o.s.Isocyanates, flammable, toxic, n.o.s.Highlighted in green: see Table 1

Highlighted in green in the ERG. If there is no fire, go to ERG Table 1 for initial isolation and protective action distances, and also use the guide. If a fire is involved, use the guide's evacuation distances and protect downwind according to Table 1.

From the 2024 Emergency Response Guidebook (ERG2024), published by U.S. Department of Transportation, PHMSA. Read the full guide in the ERG or on CAMEO Chemicals.

Identification

UN number
UN 2478
Name
Isocyanates, flammable, toxic, n.o.s. or Isocyanate solutions, flammable, toxic, n.o.s. flashpoint less than 23° C
Hazard class
Class 3: Flammable liquids
Packing group
II, III
What the class covers
Flammable liquids (and, in the U.S., combustible liquids).

U.S. Hazardous Materials Table

2 entries share this number in 49 CFR 172.101, by name, packing group or where the shipment is going.

  • UN2478Isocyanates, flammable, toxic, n.o.s. or Isocyanate solutions, flammable, toxic, n.o.s.

    flash point less than 23 degrees C

    • Technical name required in parentheses

    Special provisions: 5, A3, A7, IB2, T11, TP2, TP13, TP27, W31

    Class
    3
    Packing group
    II
    Labels
    3, 6.1

  • UN2478Isocyanates, flammable, toxic, n.o.s. or Isocyanate solutions, flammable, toxic, n.o.s.

    flash point less than 23 degrees C

    • Technical name required in parentheses

    Special provisions: 5, A3, A7, IB3, T7, TP1, TP13, TP28, W31

    Class
    3
    Packing group
    III
    Labels
    3, 6.1

From the eCFR edition of 49 CFR 172.101 dated 2026-10-05 (section last amended 2026-09-08). The eCFR is an editorial compilation, not the official legal edition. Read the current table.

About Class 3

Class 3 covers flammable liquids such as gasoline, diesel, solvents, paints and alcohols. In the United States, some liquids with higher flash points can also be shipped as combustible liquids under the same class.

See all Class 3 UN numbers

Check the official sources

For emergency response, packaging and quantity limits, use these: