Hazmat UN Number Lookup

Search hazardous materials database, check safety specifications, and view Emergency Response guides.

🏷️ Primary Hazard Class Filter

UN2601

Cyclobutane

Gases

Class 2.1

CAS Registry106-97-8

Hazchem / EAC2YE

ERG Guide Number115

49 CFR Placards & Labels

Flammable GasClass 2.1

⇩ SVG

Not listed as a Reportable Quantity (RQ) hazardous substance under §172.101 Appendix A.

Not listed as a Marine Pollutant under §172.101 Appendix B.

Regulatory Facts

Packing Group

—

Symbols (col 1)

—

Labels (col 6)

2.1

PIH Zone

—

Packaging references (49 CFR §173.xxx)

Exceptions (col 8A)

§173.306

Non-Bulk (col 8B)

§173.304

Bulk (col 8C)

§173.314, 315

Aircraft quantity limits (col 9)

Passenger / Rail (9A)

Forbidden

Cargo Aircraft Only (9B)

150 kg

Vessel stowage (col 10)

Location (10A)

Other codes (10B)

Special provisions (col 7 — §172.102)

—

Hazard Classification & Risks

Class 2.1 — Flammable gas. Ignitable at 101.3 kPa in a mixture of ≤13% with air, or with a flammable range ≥12% (49 CFR §173.115).

Transport Regulations

Hazard class 2.1. Placard/label codes: 2.1. Packaging (49 CFR §173): exceptions §306, non-bulk §304, bulk §314, 315. Quantity limits: passenger aircraft/rail Forbidden, cargo aircraft only 150 kg. Vessel stowage: B (other: 40). Classified per 49 CFR §172.101.

Shortcuts:

p Printd SVGc Copy Names Copy Spilla Copy First-Aid

Source & sourcing note

Regulatory data mirrors the U.S. 49 CFR §172.101 Hazardous Materials Table and companion columns (packaging, quantity limits, vessel stowage, special provisions) as published by the U.S. Pipeline and Hazardous Materials Safety Administration (PHMSA).

Emergency-response content is drawn from the 2024 Emergency Response Guidebook (ERG), a joint publication of PHMSA, Transport Canada, and Mexico’s SCT.

The U.S. edition of the ERG and all U.S. federal regulations are public-domain works under 17 U.S.C. §105. Descriptions on this page are plain-English paraphrases; for any compliance decision, consult the authoritative text on eCFR Title 49 and the ERG at PHMSA.dot.gov. “ERG™” is attributed to PHMSA / Transport Canada / SCT and used nominatively.