UN/NA Number Reference
DOT Class 8 Corrosive placard

UN 1818: Silicon tetrachloride

49 CFR 172.101 Hazardous Materials Table·ERG 2024

DOT Classification and Shipping

UN 1818 is assigned the proper shipping name Silicon tetrachloride 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 157)

Hazards: TOXIC and/or CORROSIVE. Reacts with water. Non-combustible in themselves.

Fire: DO NOT use water. Dry chemical, CO2, dry sand.

Spill: Do not touch. Keep material dry.

Chemical and Physical Properties

Silicon tetrachloride is a colorless, fuming liquid with a pungent odor. It is decomposed by water to hydrochloric acid with evolution of heat. It is corrosive to metals and tissue in the presence of moisture. It is used in smoke screens, to make various silicon containing chemicals, and in chemical analysis.

CAS Number: 10026-04-7
Molecular Formula: Cl4Si
Molecular Weight: 169.9 g/mol
Color / Form: Colorless, clear, mobile, fuming liquid
Odor: Suffocating odor
Boiling Point: 135.7 F
Melting Point: -94 °F (USCG, 1999)
Specific Gravity: 1.48 (sinks in water)
Vapor Pressure: 236.0 [mmHg]
Vapor Density: 7.59 g/l
Water Solubility: Miscible with benzene, ether, chloroform, petroleum ether

Special Provisions

49 CFR 172.102 special provision codes for this entry: A3, B2, B6, T10, TP2, TP7, TP13. 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 1818 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.