UN/NA Number Reference
DOT Class 5.1 Oxidizer placard

UN 2466: Potassium superoxide

49 CFR 172.101 Hazardous Materials Table·ERG 2024

DOT Classification and Shipping

UN 2466 is assigned the proper shipping name Potassium superoxide in the U.S. DOT Hazardous Materials Table (49 CFR 172.101). It is classified as a Class 5.1 Oxidizer material, Packing Group I. Required label(s): 5.1.

Packing group indicates the degree of danger within a hazard class: PG I is high danger, PG II medium, PG III low. The proper shipping name, hazard class, UN number, and packing group together form the basic shipping description that must appear on shipping papers and, where required, on the package and placard.

Emergency Response (ERG Guide 143)

Hazards: May explode from heat or contamination. Strong oxidizer. May ignite combustibles.

Fire: Flood with water from distance. Cool containers. Evacuate area if fire reaches cargo.

Spill: Keep combustibles away. Do not touch. Use water spray.

Chemical and Physical Properties

Sodium nitrite appears as a yellowish white crystalline solid. Noncombustible but will accelerate the burning of combustible material. If large quantities are involved in a fire or if the combustible material is finely divided, an explosion may result. If contaminated by ammonium compounds, spontaneous decomposition can occur and the resulting heat may ignite surrounding combustible material. Prolonged exposure heat may result in an explosion. Toxic oxides of nitrogen are produced in fires involving this material. Used as a food preservative, and to make other chemicals.

CAS Number: 7632-00-0
Molecular Formula: NNaO2
Molecular Weight: 71.097 g/mol
Color / Form: White, orthorhombic crystals
Boiling Point: Decomposes at 608 °F (NTP, 1992)
Melting Point: 520 °F (NTP, 1992)
Autoignition: 1000 °F (NTP, 1992)
Specific Gravity: 2.17 at 68 °F (USCG, 1999) - Denser than water; will sink
Water Solubility: greater than or equal to 100 mg/mL at 66 °F (NTP, 1992)
Log P: -3.7
pH: Aq soln is alkaline, pH about 9

Regulatory Data

CERCLA RQ (40 CFR 302.4)
100 lb

A release of this material at or above its CERCLA reportable quantity (100 lb) requires immediate notification to the National Response Center at 800-424-8802.

Special Provisions

49 CFR 172.102 special provision codes for this entry: A20, IB6, IP1. These codes modify the general requirements (packaging, quantity limits, exceptions) for this specific material. Look up each code in 49 CFR 172.102 for the full text.

Need the full interactive record? Open UN 2466 in the SpillNerd lookup tool for the live database entry with placard graphics, GHS pictograms, full segregation tables, and synonym search. For another material, use the UN number and chemical lookup.

Reference data compiled from the DOT Hazardous Materials Table (49 CFR 172.101), the 2024 Emergency Response Guidebook, and public chemical databases (PubChem, NIOSH, EPA). Always verify the correct shipping description against the current regulation and the manufacturer's SDS Section 14 before shipping.

Check the source: Current DOT Hazardous Materials Table · Official Emergency Response Guidebook. This compiled record is not a shipment classification or a complete response procedure.