UNunnums
2073

UN 2073Ammonia solution, relative density less than 0.880 at 15° C in water, with more than 35 percent but not more than 50 percent ammonia

Division 2.2

Non-flammable, non-toxic gases

Summary

UN 2073 is the UN number for ammonia solution, relative density less than 0.880 at 15° C in water, with more than 35 percent but not more than 50 percent ammonia. It is classed in Division 2.2 (non-flammable, non-toxic gases) of Class 2 for transport. Emergency responders use ERG guide 125.

Emergency response

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

  • Guide125Ammonia solution, with more than 35% but not more than 50% ammonia

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 2073
Name
Ammonia solution, relative density less than 0.880 at 15° C in water, with more than 35 percent but not more than 50 percent ammonia
Hazard class
Class 2: Gases
Division
2.2: Non-flammable, non-toxic gases
What the class covers
Gases which are neither flammable nor toxic, including asphyxiant and oxidizing gases.

U.S. Hazardous Materials Table

The entry for this number in 49 CFR 172.101.

  • UN2073Ammonia solution

    relative density less than 0.880 at 15 degrees C in water, with more than 35 percent but not more than 50 percent ammonia

    Special provisions: N87

    Class
    2.2
    Packing group
    None
    Labels
    2.2

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 2

Class 2 covers gases, whether compressed, liquefied, dissolved under pressure or refrigerated. Division 2.1 is flammable gases such as propane, 2.2 is non-flammable, non-toxic gases such as nitrogen, and 2.3 is toxic gases such as chlorine.

See all Class 2 UN numbers

Check the official sources

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