Hazmat UN Number Lookup

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🏷️ Primary Hazard Class Filter

NA9191

Chlorine dioxide, hydrate, frozen

Oxidizers

Class 5.1 (Primary)Class 6.1 (Subsidiary)PG II

CAS Registry7782-50-5

Hazchem / EAC1E

ERG Guide Number140

49 CFR Placards & Labels

OxidizerClass 5.1

⇩ SVG

Toxic (Poison)Class 6.1

⇩ SVG

Reportable Quantity — 10 lb (4.54 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.

Marine Pollutant

Marine-pollutant mark (§172.322) required for bulk packages by vessel; IMDG segregation and stowage rules apply.

Regulatory Facts

Packing Group

Symbols (col 1)

Labels (col 6)

5.1, 6.1

PIH Zone

—

Packaging references (49 CFR §173.xxx)

Exceptions (col 8A)

None

Non-Bulk (col 8B)

§173.229

Bulk (col 8C)

None

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)

—

Hazard Classification & Risks

Class 5.1 — Oxidizer. Yields oxygen and may cause or intensify the combustion of other materials (49 CFR §173.127). Packing Group II — medium danger.

Transport Regulations

Hazard class 5.1, Packing Group II. Placard/label codes: 5.1, 6.1. Packaging (49 CFR §173): exceptions §None, non-bulk §229, bulk §None. 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)

5.1, 6.1

PIH Zone

—

Packaging references (49 CFR §173.xxx)

Exceptions (col 8A)

None

Non-Bulk (col 8B)

§173.229

Bulk (col 8C)

None

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)

—

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.