UN/NA Number Reference
DOT Class 2.3 Toxic Gas placard

UN 3519: Boron trifluoride, adsorbed

49 CFR 172.101 Hazardous Materials Table·ERG 2024

DOT Classification and Shipping

UN 3519 is assigned the proper shipping name Boron trifluoride, adsorbed 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 trifluoride is a colorless gas with a pungent odor. It is toxic by inhalation. It is soluble in water and slowly hydrolyzed by cold water to give off hydrofluoric acid, a corrosive material. Its vapors are heavier than air. Prolonged exposure of the containers to fire or heat may result in their violent rupturing and rocketing.

CAS Number: 7637-07-2
Molecular Formula: BF3
Molecular Weight: 67.81 g/mol
Color / Form: Colorless gas
Odor: Pungent, suffocating odor
Boiling Point: -148 F
Melting Point: -196.1 °F (EPA, 1998)
Specific Gravity: 1.6 (sinks in water)
Vapor Pressure: 760 mmHg
Vapor Density: 2.4 (heavier than air)
Water Solubility: 106 % (in cold H2O) (NIOSH, 2024)

Regulatory Data

CERCLA RQ (40 CFR 302.4)
1 lb
EPCRA TPQ (40 CFR 355)
500 lb
OSHA PEL
(C) 1 (C) 3 (C) 1 ppm
NIOSH REL
C 1 ppm (3 mg/m 3 )
IDLH
25 ppm

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: 2, 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 3519 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.