UN/NA Number Reference

UN 1836: Thionyl chloride

49 CFR 172.101 Hazardous Materials Table·ERG 2024

DOT Classification and Shipping

UN 1836 is assigned the proper shipping name Thionyl chloride in the U.S. DOT Hazardous Materials Table (49 CFR 172.101). It is classified as a Class 8 Corrosive material, Packing Group I. Required label(s): 8, 6.1.

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 137)

Hazards: Produce flammable gases on contact with water. May ignite on contact with water. Some react violently with water.

Fire: DO NOT use water or foam. Use dry chemical, dry sand, or soda ash.

Spill: Do not touch. Keep material dry. Move containers from water. Dike to prevent water contact.

Chemical and Physical Properties

Thionyl chloride appears as a colorless to yellow fuming liquid with a suffocating pungent odor. Boiling point 79 °C. A lachrymator. Highly corrosive and toxic. Long-term inhalation of low concentrations or short-term inhalation of high concentrations has adverse health effects.

CAS Number: 7719-09-7

Molecular Formula: Cl2OS

Molecular Weight: 118.97 g/mol

Color / Form: Colorless to pale yellow or reddish liquid

Odor: Suffocating odor

Boiling Point: 169 F

Melting Point: -156 °F (NIOSH, 2024)

Specific Gravity: 1.64 (sinks in water)

Vapor Pressure: 100 mmHg at 70 F

Vapor Density: 4.1 (heavier than air)

Water Solubility: Reacts with water

Regulatory Data

OSHA PEL

none

NIOSH REL

C 1 ppm (5 mg/m 3 )

IDLH

Special Provisions

49 CFR 172.102 special provision codes for this entry: B6, B10, N34, T10, TP2, 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 1836 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.