UN/NA Number Reference
DOT Class 5.1 Oxidizer placard

UN 1492: Potassium persulfate

49 CFR 172.101 Hazardous Materials Table·ERG 2024

DOT Classification and Shipping

UN 1492 is assigned the proper shipping name Potassium persulfate in the U.S. DOT Hazardous Materials Table (49 CFR 172.101). It is classified as a Class 5.1 Oxidizer material, Packing Group III. 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 140)

Hazards: May cause fire or explosion. May accelerate burning. May explode from heat or contamination.

Fire: Use flooding water. Cool containers. Do not use dry chemical on large fires (ineffective).

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

Chemical and Physical Properties

Potassium persulfate appears as a white crystalline solid. Specific gravity 2.477. Decomposes below 100 °C.

CAS Number: 7727-21-1
Molecular Formula: K2O8S2
Molecular Weight: 270.33 g/mol
Color / Form: COLORLESS, TRICLINIC CRYSTALS
Odor: ODORLESS
Specific Gravity: 2.477 (sinks in water)
Vapor Density: 2.48 (heavier than air)
Water Solubility: 1.75 G IN 100 CC OF WATER @ 0 C
pH: AQUEOUS SOLN IS ACIDIC

Special Provisions

49 CFR 172.102 special provision codes for this entry: A1, A29, IB8, IP3, T1, 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 1492 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.