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1873

UN 1873Perchloric acid with more than 50 percent but not more than 72 percent acid, by mass

Division 5.1

Oxidizing substances

Summary

UN 1873 is the UN number for perchloric acid with more than 50 percent but not more than 72 percent acid, by mass. It is classed in Division 5.1 (oxidizing substances) of Class 5 for transport. Packing group I. Emergency responders use ERG guide 143.

Emergency response

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

  • Guide143Perchloric acid, with more than 50% but not more than 72% acid

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 1873
Name
Perchloric acid with more than 50 percent but not more than 72 percent acid, by mass
Hazard class
Class 5: Oxidizers and organic peroxides
Division
5.1: Oxidizing substances
Packing group
I
What the class covers
Substances which may cause or contribute to the combustion of other material, generally by yielding oxygen.

U.S. Hazardous Materials Table

The entry for this number in 49 CFR 172.101.

  • UN1873Perchloric acid

    with more than 50 percent but not more than 72 percent acid, by mass

    Special provisions: A2, N41, T10, TP1

    Class
    5.1
    Packing group
    I
    Labels
    5.1, 8

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 5

Class 5 covers substances that supply oxygen or otherwise intensify a fire. Division 5.1 is oxidizers such as ammonium nitrate and hydrogen peroxide; 5.2 is organic peroxides, which may also be thermally unstable.

See all Class 5 UN numbers

Check the official sources

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