UN 3545Articles containing organic peroxide, n.o.s.
Division 5.2
Organic peroxides
Summary
UN 3545 is the UN number for articles containing organic peroxide, n.o.s. It is classed in Division 5.2 (organic peroxides) of Class 5 for transport. Emergency responders use ERG guide 145.
Emergency response
The Emergency Response Guidebook (ERG2024) guide for this number:
- Guide145Articles containing organic peroxide, 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 3545
- Name
- Articles containing organic peroxide, n.o.s.
- Hazard class
- Class 5: Oxidizers and organic peroxides
- Division
- 5.2: Organic peroxides
- What the class covers
- Organic compounds containing the bivalent -O-O- structure, which may be thermally unstable.
U.S. Hazardous Materials Table
The entry for this number in 49 CFR 172.101.
UN3545Articles containing organic peroxide, n.o.s.
- Technical name required in parentheses
Special provisions: 131, 391
- Class
- 5.2
- Packing group
- None
- Labels
- 5.2
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 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.
Check the official sources
For emergency response, packaging and quantity limits, use these:
- CAMEO Chemicals: UN/NA 3545NOAA datasheets with the ERG response guide and isolation distances
- Emergency Response Guidebook (ERG)PHMSA's guide for first responders, free as a PDF or app
- 49 CFR 172.101 Hazardous Materials TableThe legal U.S. entry: proper shipping name, packing group, labels and special provisions