Boron trifluoride is a colorless gas with a pungent odor.
As a fumigant, in ionization chambers for detection of weak neutrons, to protect molten magnesium and its alloys from oxidation, as a flux for soldering magnesium.
Registry Numbers and Inventories.
EC Index Number
Reacts violently with water; Very toxic; Corrosive
Swiss Giftliste 1
Japan ENCS (MITI)
Melting point, °C
Boiling point, °C
Vapor pressure, mmHg
Vapor density (air=1)
Odor Threshold Odor threshold 4.50 mg/m3
1.6 g/cm3 (20 C)
Solubility in water
0.0171 m pa.s (25 C)
17.2 g/s2 (-100 C)
0.0011 (25 C)
Heat of fusion
Heat of vaporization
Hazards and Protection.
Keep in a cool, dry, dark location in a tightly sealed container or cylinder. Keep away from incompatible materials, ignition sources and untrained individuals. Secure and label area. Protect containers/cylinders from physical damage.
All chemicals should be considered hazardous. Avoid direct physical contact. Use appropriate, approved safety equipment. Untrained individuals should not handle this chemical or its container. Handling should occur in a chemical fume hood.
Proper impervious protective clothing including gloves, aprons, suits, boots, goggles, and face shields as needed to prevent skin and eye contact.
Wear positive pressure self-contained breathing apparatus (SCBA).
Keep material out of water sources and sewers. Attempt to stop leak if without undue personnel hazard. Use water spray to knock-down vapors. Do not use water on material itself.
Container of bf3 may explode in heat of fire. BF3-Diethyl etherate presents not only a container explosion hazard but also the vapors present an explosion hazard indoors, outdoors, or in sewers. Runoff to sewer also may create an explosion hazard.
Incompatible with alkyl nitrates, calcium oxide Reaction with alkali metals or alkaline earth metals (except magnesium) will cause incandescence.
When heated to decomp. Will produce. Fumes of hydrogen fluoride. Boron fluoride the toxic action of the halogenated borons is considerably influenced by their decomposition products (hydrofluoric acid-, fluoboric acid-, hydrochloric acid-).
Keep unnecessary people away; isolate hazard area and deny entry. Stay upwind; keep out of low areas. Ventilate closed spaces before entering them. Wear positive pressure breathing apparatus and full protective clothing. Evacuate area endangered by gas. Do not get water inside container. Move container from fire area if you can do it without risk. Stay away from ends of tanks. Cool containers that are exposed to flames with water from the side until well after fire is out. Isolate area until gas has dispersed.Extinguish with dry chemical, carbon dioxide, water spray, fog, or foam.
Bf3 cannot catch fire.
When heated to decomposition or upon contact with water or steam, it will produce toxic and corrosive fumes of fluorine containing compounds. Decomposes upon heating or on contact with moist air, forming toxic and corrosive fumes of boric acid and hydrofluoric acid. Reacts with alkalis and fumes in moist air, producing particulates which reduce visibility. Reacts with alkali metals, alkaline earth metals (except magnesium), alkyl nitrates, and calcium oxide. It hydrolyzes in moist air to form boric acid, hydrofluoric acid, and fluoboric acid.
When heated to decomp.
TLV: 1 ppm; 2.8 mg/m3 (ceiling values) (ACGIH 1992-1993). PDK: 0.1 mg/m3 (USSR 1972). OSHA PEL: C 1 ppm (3 mg/m3) NIOSH REL: C 1 ppm (3 mg/m3) NIOSH IDLH: 25 ppm
Acute exposure to boron trifluoride gas has resulted in rapid loss of consciousness.
Acute inhalations have resulted in hypoxemia.
Skin irritation is expected on contact. When soaked into a cotton ball and placed on the skin for 1 to 2 days, boron fluoride left a hf type burn.
Teeth: Rats exposed to 15 to 100 ppm developed hypoplasia of the teeth and excessive fluoride deposition. Nose bleed and nasal dryness has been reported in humans.
WIth acute ingestions, severe gastritis or gastroenteritis with abdominal pain may be seen. Vomiting begins within an hour. Diarrhea with watery, tarry feces may follow with dehydration. Liver injury will occur.
Move victim to fresh air. Apply artificial respiration if victim is not breathing. Do not use mouth-to-mouth method if victim ingested or inhaled the substance; induce artificial respiration with the aid of a pocket mask equipped with a one-way valve or other proper respiratory medical device. Administer oxygen if breathing is difficult. Effects may be delayed.
Remove contaminated clothing and wash exposed area thoroughly with soap and water. A physician should examine the area if irritation or pain persists.
Irrigate exposed eyes with copious amounts of tepid water for at least 15 minutes. If irritation, pain, swelling, lacrimation, or photophobia persist, the patient should be seen in a health care facility.
USCG CHRIS Code
Std. Transport #