Agent Name

Boron trifluoride

CAS Number




Major Category

Toxic Gases & Vapors


Anca 1040; Borane, trifluoro-; Boron fluoride; Boron fluoride (BF3); Fluorure de bore [French]; Trifluoroborane; Trifluoroboron; [ChemIDplus] UN1008


Corrosive Gases


Colorless gas with a pungent, suffocating odor; Note: Forms dense white fumes in moist air. Shipped as a nonliquefied compressed gas; [NIOSH] Vapor density = 2.34 (heavier than air); Burke, p. 100]


Used as a catalyst in organic synthesis, including olefin polymerization, petroleum cracking and desulfurization, and epoxy curing; Has been used in soldering flux, as a fumigant, for neutron measurement, and to protect molten magnesium; Also used in electronics industry (electrochemical high-temperature cells) and to produce microchips (metal etching agent); [ACGIH]


Corrosive to skin; [Quick CPC] Toxic effects in animals include pneumonitis and dental fluorosis; At 1.5 ppm 5 days a week for up to 6 months, there was evidence of mild pneumonitis. [ACGIH] Burns caused by boron trifluoride are not as severe as those caused by hydrogen fluoride. [National Research Council, Prudent Practices for Handling Hazardous Chemicals in Laboratories. 1981] A corrosive substance that causes lacrimation and may cause lung edema after inhalation of high concentrations; [ICSC] Decomposes in contact with moisture or when heated producing boric acid, HF, and fluoboric acid; [CAMEO] Reacts violently with water; Causes severe burns; Highly toxic by inhalation; [Alfa Aesar MSDS] See "FLUORIDES."

Reference Link

NIOSH Occupational Health Guidelines for Chemical Hazards: Boron trifluoride

Exposure Assessment
Skin Designation (ACGIH)

Insufficient data




0.1 ppm

Ceiling (ACGIH)

0.7 ppm


Ceiling(OSHA) = 1 ppm

Excerpts from Documentation for IDLHs

Other animal data: Exposure to a concentration of 100 ppm resulted in a uniformly high mortality rate in six laboratory species, and 15 ppm was occasionally fatal in 30-day studies [Stokinger et al. 1953]. Rats exposed 6 hours/day to 24 ppm or 2 weeks to 9 ppm showed signs of respiratory irritation, depression of body weight, increased lung weights, and depressed liver weights [Rusch et al. 1986].

Odor Threshold Low

1.5 ppm

Lethal Concentration

LC50 (rat) = 1,180 mg/m3/4hr

Explanatory Notes

Odor threshold from AIHA;

Half Life

Whole body (for boron administered orally): complete removal within 96 hours; [TDR, p. 205]

Reference Link

ICSC: Boron trifluoride

Adverse Effects


Toxic Pneumonitis



Skin Burns

Links to Other NLM Databases
Health Studies

Human Health Effects from Hazardous Substances Data Bank:

Toxicity Information


Chemical Information

Search ChemIDplus

Related Information in HazMap

Occupational diseases associated with exposure to this agent:


Industrial Processes with risk of exposure: