UN/NA Number Reference
DOT Class 6.1 Toxic Substance placard

UN 3246: Methanesulfonyl chloride

49 CFR 172.101 Hazardous Materials Table·ERG 2024

DOT Classification and Shipping

UN 3246 is assigned the proper shipping name Methanesulfonyl chloride in the U.S. DOT Hazardous Materials Table (49 CFR 172.101). It is classified as a Class 6.1 Toxic Substance material, Packing Group II. Required label(s): 6.1, 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 156)

Hazards: TOXIC or CORROSIVE. FLAMMABLE. Vapors may travel to ignition source.

Fire: Alcohol-resistant foam, dry chemical, CO2. Water spray for cooling only.

Spill: Eliminate ignition sources. Do not touch. Ventilate area.

Chemical and Physical Properties

Methanesulfonyl chloride appears as a pale yellow corrosive liquid. More dense than water and insoluble in water. Very toxic by ingestion, inhalation, or skin absorption.

CAS Number: 124-63-0
Molecular Formula: CH3ClO2S
Molecular Weight: 114.55 g/mol
Color / Form: Pale yellow liquid
Odor: Unpleasant odor
Boiling Point: 62 C
Melting Point: Freezing point: -32 °C
Flash Point: >110 °C
Specific Gravity: 1.4805 (sinks in water)
Vapor Pressure: 3.09 [mmHg]
Vapor Density: 3.9 (heavier than air)
Water Solubility: Soluble in most organic solvents

Special Provisions

49 CFR 172.102 special provision codes for this entry: 2, B9, B14, B32, T20, TP2, TP13, TP38, TP45. 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 3246 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.