UNunnums
2921

UN 2921Corrosive solids, flammable, n.o.s.

Class 8

Corrosives

Summary

UN 2921 is the UN number for corrosive solids, flammable, n.o.s. It is classed in Class 8 (corrosives) for transport. Packing group I or II, depending on the form. Emergency responders use ERG guide 134.

Emergency response

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

  • Guide134Corrosive solid, flammable, n.o.s.

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 2921
Name
Corrosive solids, flammable, n.o.s.
Hazard class
Class 8: Corrosives
Packing group
I, II
What the class covers
Substances which can damage living tissue or other goods and materials on contact.

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.

  • UN2921Corrosive solids, flammable, n.o.s.

    • Technical name required in parentheses

    Special provisions: IB6, T6, TP33

    Class
    8
    Packing group
    I
    Labels
    8, 4.1

  • UN2921Corrosive solids, flammable, n.o.s.

    • Technical name required in parentheses

    Special provisions: IB8, IP2, IP4, T3, TP33

    Class
    8
    Packing group
    II
    Labels
    8, 4.1

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 8

Class 8 covers corrosive substances such as acids, alkalis and battery fluid, which can destroy skin or corrode metal on contact.

See all Class 8 UN numbers

Check the official sources

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