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🏷️ Primary Hazard Class Filter

UN2545

Hafnium powder, dry

Spontaneously Combustible

Class 4.2PG I

CAS RegistryN/A

Hazchem / EAC1Y

ERG Guide Number133

49 CFR Placards & Labels

Spontaneously CombustibleClass 4.2

⇩ 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)

4.2

PIH Zone

—

Packaging references (49 CFR §173.xxx)

Exceptions (col 8A)

None

Non-Bulk (col 8B)

§173.211

Bulk (col 8C)

§173.242

Aircraft quantity limits (col 9)

Passenger / Rail (9A)

Forbidden

Cargo Aircraft Only (9B)

Forbidden

Vessel stowage (col 10)

Location (10A)

Other codes (10B)

13, 148

Special provisions (col 7 — §172.102)

W31

Hazard Classification & Risks

Class 4.2 — Spontaneously combustible; pyrophoric (ignites within 5 minutes of air contact) or self-heating (49 CFR §173.124). Packing Group I — great danger.

Transport Regulations

Hazard class 4.2, Packing Group I. Placard/label codes: 4.2. Special provisions: W31. Packaging (49 CFR §173): exceptions §None, non-bulk §211, bulk §242. Quantity limits: passenger aircraft/rail Forbidden, cargo aircraft only Forbidden. Vessel stowage: D (other: 13, 148). Classified per 49 CFR §172.101.

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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.

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Regulatory Facts

Packing Group

Symbols (col 1)

—

Labels (col 6)

4.2

PIH Zone

—

Packaging references (49 CFR §173.xxx)

Exceptions (col 8A)

None

Non-Bulk (col 8B)

§173.211

Bulk (col 8C)

§173.242

Aircraft quantity limits (col 9)

Passenger / Rail (9A)

Forbidden

Cargo Aircraft Only (9B)

Forbidden

Vessel stowage (col 10)

Location (10A)

Other codes (10B)

13, 148

Special provisions (col 7 — §172.102)

W31

Source & sourcing note

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