UN/NA Number Reference
DOT Class 2.3 Toxic Gas placard

UN 1741: Boron trichloride

49 CFR 172.101 Hazardous Materials Table·ERG 2024

DOT Classification and Shipping

UN 1741 is assigned the proper shipping name Boron trichloride in the U.S. DOT Hazardous Materials Table (49 CFR 172.101). It is classified as a Class 2.3 Toxic Gas material. Required label(s): 2.3, 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 125)

Hazards: TOXIC. Corrosive. Causes burns. May be fatal if inhaled. Vapors heavier than air.

Fire: Use water spray or fog. Do not get water inside containers.

Spill: Fully encapsulating suit required. Stop leak if safe. Use water spray.

Chemical and Physical Properties

Boron trichloride appears as a colorless gas with a pungent odor. Fumes irritate the eyes and mucous membranes. Corrosive to metals and tissue and is toxic. Under prolonged exposure to fire or intense heat, the containers may rupture violently and rocket. Used as a catalyst in chemical manufacture, in soldering fluxes, and for many other uses.

CAS Number: 10294-34-5
Molecular Formula: BCl3
Molecular Weight: 117.2 g/mol
Color / Form: Gas at room temperature
Odor: Pungent, irritating odor
Boiling Point: 54.5 F
Melting Point: -161 °F (EPA, 1998)
Specific Gravity: 1.35 (sinks in water)
Vapor Pressure: 760 mmHg at 54.86 F
Vapor Density: 4.03 (heavier than air)
Water Solubility: Solubility in water: reaction

Regulatory Data

CERCLA RQ (40 CFR 302.4)
1 lb
EPCRA TPQ (40 CFR 355)
500 lb

A release of this material at or above its CERCLA reportable quantity (1 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: 3, B9, B14. 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 1741 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.