UN/NA Number Reference
DOT Class 8 Corrosive placard

UN 2225: Benzenesulfonyl chloride

49 CFR 172.101 Hazardous Materials Table·ERG 2024

DOT Classification and Shipping

UN 2225 is assigned the proper shipping name Benzenesulfonyl chloride in the U.S. DOT Hazardous Materials Table (49 CFR 172.101). It is classified as a Class 8 Corrosive material, Packing Group III. 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 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

Benzenesulfonyl chloride appears as a colorless to slightly yellow solid that melts at approximately 40 °F. Very irritating to skin, eyes and mucous membranes. May emit toxic fumes when heated to high temperatures. Used to make dyes and other chemicals.

CAS Number: 98-09-9
Molecular Formula: C6H5ClO2S
Molecular Weight: 176.62 g/mol
Color / Form: COLORLESS, OILY LIQUID
Boiling Point: 484.7 F
Melting Point: 58.1 °F (USCG, 1999)
Flash Point: greater than 233.6 F
Specific Gravity: 1.3842 (sinks in water)
Vapor Pressure: 0.06 [mmHg]
Water Solubility: INSOL IN WATER

Regulatory Data

CERCLA RQ (40 CFR 302.4)
100 lb
RCRA Waste Code(s)
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A release of this material at or above its CERCLA reportable quantity (100 lb) requires immediate notification to the National Response Center at 800-424-8802.

Special Provisions

49 CFR 172.102 special provision codes for this entry: IB3, T4, TP1. 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 2225 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.