Hazmat UN Number Lookup

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🏷️ Primary Hazard Class Filter

UN1381

Phosphorus, white dry or Phosphorus, white, under water or Phosphorus white, in solution or Phosphorus, yellow dry or Phosphorus, yellow, under water or Phosphorus, yellow, in solution

Spontaneously Combustible

Class 4.2 (Primary)Class 6.1 (Subsidiary)PG I

CAS RegistryN/A

Hazchem / EAC1Y

ERG Guide Number133

49 CFR Placards & Labels

Spontaneously CombustibleClass 4.2

⇩ SVG

Toxic (Poison)Class 6.1

⇩ SVG

Reportable Quantity — 1 lb (0.454 kg)

Any release meeting or exceeding this amount must be reported to the National Response Center at 1-800-424-8802 under 40 CFR 302.6 and 49 CFR 171.15.

Severe Marine Pollutant (S.M.P.)

Marine-pollutant mark (§172.322) required for bulk packages by vessel; IMDG segregation and stowage rules apply. S.M.P. status may extend the mark to non-bulk single packages.

Regulatory Facts

Packing Group

Symbols (col 1)

—

Labels (col 6)

4.2, 6.1

PIH Zone

—

Packaging references (49 CFR §173.xxx)

Exceptions (col 8A)

None

Non-Bulk (col 8B)

§173.188

Bulk (col 8C)

§173.243

Aircraft quantity limits (col 9)

Passenger / Rail (9A)

Forbidden

Cargo Aircraft Only (9B)

Forbidden

Vessel stowage (col 10)

Location (10A)

Other codes (10B)

—

Special provisions (col 7 — §172.102)

B9 B26 N34 T9 TP3 TP31 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, 6.1. Special provisions: B9, B26, N34, T9, TP3, TP31, W31. Packaging (49 CFR §173): exceptions §None, non-bulk §188, bulk §243. Quantity limits: passenger aircraft/rail Forbidden, cargo aircraft only Forbidden. Vessel stowage: E. 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.

Regulatory Facts

Packing Group

Symbols (col 1)

—

Labels (col 6)

4.2, 6.1

PIH Zone

—

Packaging references (49 CFR §173.xxx)

Exceptions (col 8A)

None

Non-Bulk (col 8B)

§173.188

Bulk (col 8C)

§173.243

Aircraft quantity limits (col 9)

Passenger / Rail (9A)

Forbidden

Cargo Aircraft Only (9B)

Forbidden

Vessel stowage (col 10)

Location (10A)

Other codes (10B)

—

Special provisions (col 7 — §172.102)

B9 B26 N34 T9 TP3 TP31 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.