UN/NA Number Reference
DOT Class 6.1 Toxic Substance placard

UN 2249: Dichlorodimethyl ether, symmetrical

49 CFR 172.101 Hazardous Materials Table·ERG 2024

DOT Classification and Shipping

UN 2249 is assigned the proper shipping name Dichlorodimethyl ether, symmetrical 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 I. Required label(s): 6.1, 3.

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 131)

Hazards: HIGHLY FLAMMABLE. TOXIC. May be fatal if inhaled, swallowed, or absorbed through skin. Vapors heavier than air.

Fire: Small: dry chemical, CO2, water spray, alcohol-resistant foam. Large: water spray, fog, alcohol-resistant foam.

Spill: Eliminate ignition sources. Do not touch. Stop leak if safe. Use vapor-suppressing foam. Ventilate area.

Chemical and Physical Properties

Dichlorodimethyl ether, symmetrical appears as a colorless volatile liquid with a chloroform-like odor. Toxic by inhalation, skin absorption and ingestion. Dangerous fire risk - flash point below 0 °F. Vapors much denser than air. Insoluble in water and denser than water. Used to make paints and varnish, and as a solvent.

CAS Number: 542-88-1
Molecular Formula: C2H4Cl2O
Molecular Weight: 114.96 g/mol
Color / Form: Colorless liquid
Odor: Suffocating odor
Boiling Point: 223 F
Melting Point: -42.7 °F (EPA, 1998)
Flash Point: Less than 66.2F
Specific Gravity: 1.315 (sinks in water)
Vapor Pressure: 30 mmHg at 71.6 F
Vapor Density: 4 (heavier than air)
Water Solubility: Reacts with water
Log P: log Kow = 1.04

Regulatory Data

CERCLA RQ (40 CFR 302.4)
10 lb
EPCRA TPQ (40 CFR 355)
100 lb
OSHA PEL
0.001 ppm See Section 5209
NIOSH REL
Ca
IDLH
Ca [N
RCRA Waste Code(s)
[object Object]

A release of this material at or above its CERCLA reportable quantity (10 lb) requires immediate notification to the National Response Center at 800-424-8802.

Need the full interactive record? Open UN 2249 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.