UN 3423: Tetramethylammonium hydroxide, solid

DOT Classification and Shipping

UN 3423 is assigned the proper shipping name Tetramethylammonium hydroxide, solid in the U.S. DOT Hazardous Materials Table (49 CFR 172.101). It is classified as a Class 8 Corrosive material, Packing Group II. Required label(s): 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 153)

Hazards: TOXIC. Combustible. Corrosive. Causes burns. Toxic fumes when heated.

Fire: Small: dry chemical, CO2, water spray. Large: water spray, foam.

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

Chemical and Physical Properties

Tetramethylammonium hydroxide is a solid in the hydrated form or a colorless liquid with a strong ammonia-like odor. It is soluble in water. It is corrosive to metals and tissue.

Special Provisions

49 CFR 172.102 special provision codes for this entry: B2, IB8, IP2, IP4, 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 3423 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.