UNunnums
0197

UN 0197Signals, smoke

Division 1.4G

Explosives

Summary

UN 0197 is the UN number for signals, smoke. It is classed in Division 1.4G (explosives) of Class 1 for transport. Emergency responders use ERG guide 114.

Emergency response

The ERG doesn't list explosives by UN number. It covers Division 1.4 under this entry:

  • Guide114Explosives, division 1.4 or 1.6

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 0197
Name
Signals, smoke
Hazard class
Class 1: Explosives
Division
1.4G: ExplosivesG is the compatibility group, which decides which explosives can travel together.
What the class covers
Explosives which present no significant blast hazard.

U.S. Hazardous Materials Table

The entry for this number in 49 CFR 172.101.

  • UN0197Signals, smoke

    Class
    1.4G
    Packing group
    None
    Labels
    1.4G

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 1

Class 1 covers explosive substances and articles, from blasting explosives to fireworks and ammunition. It's split into six divisions by how the material behaves in a fire or accident, from 1.1 (mass explosion hazard) to 1.6 (extremely insensitive articles). Explosives also carry a compatibility group letter, such as 1.4S, which governs which explosives can be transported together.

See all Class 1 UN numbers

Check the official sources

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