UN/NA Number Reference
DOT Class 2.2 Non-Flammable Gas placard

UN 3497: Krypton, refrigerated liquid

49 CFR 172.101 Hazardous Materials Table·ERG 2024

DOT Classification and Shipping

UN 3497 is assigned the proper shipping name Krypton, refrigerated liquid in the U.S. DOT Hazardous Materials Table (49 CFR 172.101). It is classified as a Class 2.2 Non-Flammable Gas material. Required label(s): 2.2.

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 120)

Hazards: Vapors may cause dizziness or asphyxiation. Contact with liquid may cause frostbite. Containers may rocket if heated.

Fire: Use agent appropriate for surrounding fire. Cool containers with water.

Spill: Do not touch. Stop leak if safe. Use water spray to reduce vapor. Ventilate area.

Chemical and Physical Properties

Krypton, compressed, is a colorless, odorless gas. It is shipped as a liquid under its own vapor pressure. Contact with the liquid may cause frostbite to unprotected skin. It can asphyxiate by displacement of air. Exposure of the container to prolonged heat or fire may cause it to rupture violently and rocket.

CAS Number: 7439-90-9
Molecular Formula: Kr
Molecular Weight: 83.80 g/mol
Boiling Point: -153Â °C
Melting Point: -157 °C
Vapor Density: 1
Water Solubility: Solubility in water: none
Log P: 1.2 (estimated)

Special Provisions

49 CFR 172.102 special provision codes for this entry: 155, IB6, IP2, T3, TP33. 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 3497 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.