UN/NA Number Reference
DOT Class 6.1 Toxic Substance placard

UN 2664: Dibromomethane

49 CFR 172.101 Hazardous Materials Table·ERG 2024

DOT Classification and Shipping

UN 2664 is assigned the proper shipping name Dibromomethane 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 III. Required label(s): 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 160)

Hazards: Non-flammable in most cases. Toxic by inhalation. Vapors heavier than air. Decomposes in fire producing toxic gases including phosgene.

Fire: Use water spray, dry chemical, CO2, foam.

Spill: Ventilate area. Absorb with earth/sand. Prevent runoff to waterways.

Chemical and Physical Properties

Dibromomethane appears as a colorless liquid with a pleasant odor. Insoluble in water and denser than water. May be toxic by ingestion. Used as a solvent and as a motor fuel.

CAS Number: 74-95-3
Molecular Formula: CH2Br2
Molecular Weight: 173.83 g/mol
Color / Form: Clear, colorless liquid
Boiling Point: 206.6 F
Melting Point: -62.5 °F (USCG, 1999)
Autoignition: 515 °C
Specific Gravity: 2.497 (sinks in water)
Vapor Pressure: 87.89 mmHg
Vapor Density: 6.05 (heavier than air)
Water Solubility: 11.70 g/1000 g water @ 15 C
Log P: log Kow = 1.70

Regulatory Data

CERCLA RQ (40 CFR 302.4)
1000 lb
RCRA Waste Code(s)
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A release of this material at or above its CERCLA reportable quantity (1000 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 2664 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.