UN 3255: tert-Butyl hypochlorite

DOT Classification and Shipping

UN 3255 is assigned the proper shipping name tert-Butyl hypochlorite in the U.S. DOT Hazardous Materials Table (49 CFR 172.101). It is classified as a Class 4.2 Spontaneously Combustible material, Packing Group I. Required label(s): 4.2, 8.

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 135)

Hazards: Spontaneously combustible. May reignite after fire is extinguished. May burn rapidly.

Fire: Small: dry chemical, sand, earth. Large: flooding water. Do NOT use foam.

Spill: Do not touch. Cover with dry earth/sand. Do not get water on spilled substance.

Chemical and Physical Properties

Need the full interactive record? Open UN 3255 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.