Boron trifluoride

Toxic Gases & Vapors -> Corrosive Gases

Reactive agents - 1st degree

Pungent, suffocating odor

Pungent, irritating

1.6 (EPA, 1998) - Denser than water; will sink

1.57 at -100.4 °C/4 °C (liquid); 3.07666 g/L (gas at STP)

Density: 2.772 g/L

1.6

2.99 @25 °C

2.38(relative gas density)

106 % (in cold H2O) (NIOSH, 2024)

Solubility in water: 332 g/100 g at 0 °C; some hydrolysis occurs to form fluoboric and boric acids

Soluble in cold water, hydrolyzes in hot water

Soluble in concentrated sulfuric acid and most organic solvents

Soluble in concentrated nitric acid, benzene, dichlorobenzene, chloroform, carbon tetrachloride, carbon disulfide

Solubility in anhydrous sulfuric acid: 1.94 g/100 g; soluble in most saturated and halogenated hydrocarbons and in aromatic compounds

-148 °F at 760 mmHg (NIOSH, 2024)

-99.9 °C

-100 °C

-148 °F

-100 °C @760 [mm Hg]

-148 °F

Dangerous; when heated to decomposition or upon contact with water or steam, will produce toxic and corrosive fumes of /hydrogen fluoride/.

The toxic action of the halogenated borons is considerably influenced by their decomposition products (hydrofluoric acid-, fluoboric acid-, hydrochloric acid-). /Halogenated borons/

-196.1 °F (EPA, 1998)

-126.8 °C

-127 °C

-196 °F

-126.8 °C

-196 °F

Danger

H314: Causes severe skin burns and eye damage [Danger Skin corrosion/irritation]

P260, P264, P271, P280, P284, P301+P330+P331, P302+P361+P354, P304+P340, P305+P354+P338, P316, P320, P321, P363, P403+P233, P405, and P501 (click each P-code to see the statement)

Danger

H280 (69.9%): Contains gas under pressure; may explode if heated [Warning Gases under pressure]

P260, P261, P264, P264+P265, P271, P280, P284, P301+P330+P331, P302+P361+P354, P304+P340, P305+P354+P338, P316, P317, P319, P320, P321, P363, P403+P233, P405, P410+P403, and P501 (click each P-code to see the statement)

Chemical: Borane, trifluoro-

Status: Active Update: 17-04-2020 https://echa.europa.eu/registration-dossier/-/registered-dossier/5175

Borane, trifluoro-: HSNO Approval: HSR001055 Approved with controls

The New Jersey Worker and Community Right to Know Act requires public and private employers to provide information about hazardous substances at their workplaces. (N.J.S.A. 34:5A-1 et. seq.)

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. (EPA, 1998)

· Some may burn but none ignite readily.

Not combustible.

Nonflammable compressed gas.

Nonflammable

Highly toxic; may cause death or permanent injury after very short exposure to small quantities. Substance is irritating to the eyes, the skin, and the respiratory tract. (EPA, 1998)

· TOXIC and/or CORROSIVE; may be fatal if inhaled, ingested or absorbed through skin.

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.

1008 125

1008 125

NIOSH; Criteria Document: Boron trifluoride (1976) DHEW Pub. NIOSH 77-122

USEPA; Chemical Profiles: Boron trifluoride 1-3 (1985)

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.

In case of fire in the surroundings: use appropriate extinguishing media. In case of fire: keep cylinder cool by spraying with water. NO direct contact with water.

Fresh air, rest. Half-upright position. Artificial respiration may be needed. Refer immediately for medical attention.

Wear protective gloves when administering first aid. Remove contaminated clothes. Rinse and then wash skin with water and soap. Refer immediately for medical attention.

Rinse with plenty of water (remove contact lenses if easily possible). Refer immediately for medical attention.

· CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper not available or no answer, refer to appropriate telephone number listed on the inside back cover.

· Do not touch or walk through spilled material.

Warning: Boron trifluoride is extremely corrosive. Caution is advised.

General First Aid:

(General first aid procedures)

· Wear positive pressure self-contained breathing apparatus (SCBA).

TIH (Toxic Inhalation Hazard) - Term used to describe gases and volatile liquids that are toxic when inhaled. Some are TIH materials themselves, e.g., chlorine, and some release TIH gases when spilled in water, e.g., chlorosilanes. [ERG 2016].

Approach fire from upwind to avoid hazardous vapors and toxic decomposition products. Use water spray to keep fire-exposed containers cool. Extinguish fire using agent suitable for surrounding fire.

If material involved in fire: Extinguish using agent suitable for type of surrounding fire (material itself does not burn or burns with difficulty). Cool all affected containers with flooding quantities of water. Apply water from as afar a distance as possible. Do not use water on material itself. If large quantities of combustibles are involved, use water in flooding quantities as spray and fog. Use water spray to knock-down vapors.

Approach fire from upwind to avoid hazardous vapors and toxic decomposition products. Use water spray to keep fire-exposed containers cool. Extinguish fire using agent suitable for surrounding fire.

Store in cool, dry, well-ventilated location. Outside or detached storage is preferred. Separate from water, active metals, monomers.

Store in a cool, dry, well ventilated location. Outside or detached storage is preferred. Separate from water, active metals, monomers.

Fireproof if in building. Separated from alkali metals, alkaline earth metals, alkyl nitrates and lime. Cool.

Cylinders of boron trifluoride must be secured against dropping, falling and rupture. Storage areas must be free of excess moisture, and to minimize corrosion, the cylinders must not be stored on damp ground. No boron trifluoride storage area may contain explosives or flammable materials. Laboratories are advised to store boron trifluoride cylinders in exhaust hoods and to maintain design airflows.

Approach release from upwind. Stop or control the leak, if this can be done without undue risk. Use water spray to cool and disperse vapors and protect personnel. Avoid wetting leak or spill area. Releases may require isolation or evacuation.

Evacuate danger area! Consult an expert! Ventilation. NEVER direct water jet on liquid. Remove fumes with fine water spray (extra personal protection: complete protective clothing including self-contained breathing apparatus).

Ventilate area of leak to disperse the gas. Stop flow of gas. If source of leak is cylinder and leak cannot be stopped in place, remove ... to safe place in open air, and repair leak or allow cylinder to empty.

SRP: The most favorable course of action is to use an alternative chemical product with less inherent propensity for occupational harm/injury/toxicity or environmental contamination. Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material's impact on air quality; potential migration in soil or water; effects on animal and plant life; and conformance with environmental and public health regulations.

Chemical reaction with water to form boric acid and fluoroboric acid. The fluoroboric acid is reacted with limestone forming boric acid and calcium fluoride. The boric acid may be discharged into a sanitary sewer system while the calcium fluoride may be recovered or landfilled.

The substance can be absorbed into the body by inhalation. Serious local effects on contact with skin.

inhalation, skin and/or eye contact

Burning sensation. Cough. Laboured breathing.

Redness. Burning sensation. Pain. ON CONTACT WITH LIQUID: FROSTBITE.

Redness. Pain. Blurred vision.

irritation eyes, skin, nose, respiratory system; epistaxis (nosebleed); eye, skin burns; In Animals: pneumonitis; kidney damage

In the absence of a suitable monitoring method ... medical surveillance, including comprehensive placement and annual periodic exam /should/ be made available to all workers ... in areas where boron trifluoride is manufactured, used, handled, or is evolved as a result of chemical processes.

Initial Medical Examination: ... Resp system and kidneys should be stressed. The skin and eyes should be examined for evidence of chronic disorders. Surveillance of the lung is indicated. ... Examinations should be repeated on an annual basis.

Preplacement examinations should include a physical examination giving particular attention to the respiratory system and using appropriate pulmonary function tests such as FEV, and FVC.

Fluoride levels in urine should be checked periodically. /Fluoride and cmpd/

No specific considerations are needed for boric acid or borates except for general health and liver and kidney function. /Boric acid and borates/

/HUMAN EXPOSURE STUDIES/ In... manufacturing plant in USA, physical exams initiated in 1974 for small group of workers including 7 with present and 6 with past exposures to boron trifluoride or other fluorides, ranging from 1 to 27 yr. Five of the 7 currently exposed, and 3 of 6 with previous exposures showed lower pulmonary function (forced VC and FEV) than predicted for normal population. Lowered pulmonary function was severe in 1, moderate in 3, and minimal in 1 of 7 currently exposed who had average exposure of 13 yr. X-rays were negative, and no urinary fluorine concentrations were above acceptable preshift concentrations of 4 mg/L.

/SIGNS AND SYMPTOMS/ /Possible effects of exposure on/ skin /include/ redness, burning sensation, pain, and on contact with liquid: frostbite.

/SIGNS AND SYMPTOMS/ /Possible effects of exposure by/ inhalation /include/ corrosion, burning sensation, cough, and labored breathing.

/SIGNS AND SYMPTOMS/ EFFECTS OF SHORT-TERM EXPOSURE: Corrosive. Tear drawing. The substance is corrosive to the eyes, the skin and the respiratory tract. Inhalation of the gas may cause lung edema. Rapid evaporation of the liquid may cause frostbite.

For more Human Toxicity Excerpts (Complete) data for BORON TRIFLUORIDE (13 total), please visit the HSDB record page.

/LABORATORY ANIMALS: Acute Exposure/ A 4-hour LC50 in rats was reported as 436 ppm for boron trifluoride dihydrate, which is a related compound formed through hydrolysis in moist air. Outward signs, including gasping, excessive oral and nasal discharge, and lacrimation, were observed. /Boron trifluoride dihydrate/

/LABORATORY ANIMALS: Acute Exposure/ In a two-week study, rats exposed at 67 ppm for 6 hours/day died before the sixth daily exposure. Histopathology showed kidney damage (necrosis and pyknosis of the proximal tubular epithelium).

/LABORATORY ANIMALS: Acute Exposure/ The principal feature in acute action... is the irritation of mucous membranes of respiratory tract and eyes. In animal acute experiments, a concentration of 42 mg/cu m proved fatal in some cases. Examination revealed a fall in inorganic phosphorus level in blood and autopsy showed pneumonia and degenerative changes in renal tubules. Long-term (4 month) exposure to 3 and 10 mg/cu m... produced irritation of respiratory tract, dysproteinemia, reduction in cholinesterase activity and increased nervous system lability. Exposure to high concentration results in reduction of acetyl carbonic acid and inorganic phosphorus levels in blood, and dental fluorosis.

/LABORATORY ANIMALS: Acute Exposure/The objectives of this study were to examine the respiratory irritancy of boron trifluoride (BF(3)) and fluorosulfonic acid (FSA) following acute inhalation exposure. Testing was conducted using groups of 10 male and 10 female rats (BF(3)) or groups of 6 male rats (FSA). Rats were exposed for a single 4-hr period (BF(3)) or a single 1-hr period (FSA) and necropsied 1 or 14 days after exposure (BF(3)) or 14 days after exposure (FSA). Measurements consisted of clinical signs, body weight, kidney and lung weight, histopathology (BF(3)), and breathing parameters (FSA) and were used to evaluate the possible irritating effects of these compounds. The results indicated treatment-related findings in the larynx and trachea in the rats exposed to 74.4 mg/cu m BF(3), consisting of ventral cartilage necrosis, hemorrhage, and an increase in ventral epithelial hyperplasia and ventral inflammatory cell inflammation 24 hr postexposure. In the animals sacrificed 14 days postexposure, the only notable observation was ventral cartilage necrosis, present in 2 animals. The next lower level tested, 24.6 mg/cu m BF, was considered a no-observed-adverse-effects level (NOAEL). A concentration of 4125 mg/m(3) FSA resulted in a clearly decreased breathing rate during and shortly after exposure with 67% (4/6) mortality on days 5-9 after exposure. A concentration of 845 mg/m(3) FSA resulted in only minor signs of irritation, consisting of slight changes in breathing pattern shorlty after exposure. The results of the present 4-h inhalation study with BF(3) indicated that respiratory irritation was present at a level of 74.4 mg/cu m whereas 24.6 mg/cu m was a NOAEL. A single 1-hr exposure to 845 mg/cu m FSA resulted in only minor signs of respiratory irritation, indicating that on a mass basis FSA is no more toxic or irritating than hydrogen fluoride (HF) or sulfuric acid.

For more Non-Human Toxicity Excerpts (Complete) data for BORON TRIFLUORIDE (22 total), please visit the HSDB record page.

According to the 2006 TSCA Inventory Update Reporting data, the number of persons reasonably likely to be exposed in the industrial manufacturing, processing, and use of boron trifluoride is 1 to 99; the data may be greatly underestimated(1).

NIOSH (NOES Survey 1981-1983) has statistically estimated that 3,819 workers (524 of these are female) are potentially exposed to boron trifluoride(1). Occupational exposure to boron trifluoride may occur through inhalation and dermal contact with this compound at workplaces where boron trifuloride is produced or used(SRC).

Inhalation of vapors or skin and eye contact.

The following list includes some common operation in which exposure to boron trifluoride may occur ... Use as a Lewis acid catalyst for alkylation of aromatic compounds; use in polymer technology in manufacture of phenolic and epoxy resins; Use in synthesis of other boron-containing organic and inorganic compounds; use in purification of hydrocarbons to remove unsaturates and sulfur, nitrogen, and oxygen containing compounds; Use in nuclear technology for separation of boron isotopes; as a filling gas for neutron counters; Use in metallurgy as flux and antioxidant; use as flame coloring agent for liquefied petroleum gas.

For more Probable Routes of Human Exposure (Complete) data for BORON TRIFLUORIDE (7 total), please visit the HSDB record page.

The chemistry of boron is dominated by its tendency to form stable bonds with electronegative atoms, especially oxygen. Reduced boron compounds (halides, hydrides, alkyls and aryls) tend to oxidize and hydrolyze readily, and would be expected to be converted into various boron-oxide compounds in the environment. Inorganic boron compounds are nonvolatile and would not be expected to volatilize from moist or dry soil surfaces. (SRC)

Releases of CERCLA hazardous substances are subject to the release reporting requirement of CERCLA section 103, codified at 40 CFR part 302, in addition to the requirements of 40 CFR part 355. Boron trifluoride is an extremely hazardous substance (EHS) subject to reporting requirements when stored in amounts in excess of its threshold planning quantity (TPQ) of 500 lbs.

Boron trifluoride

1

5000

26.87

45

Toxic chemical that can be released at a facility.

(CA) CALIFORNIA 1000 ug/L /Boron/

(NH) NEW HAMPSHIRE 630 ug/L /Boron/

(ME) MAINE 1,400 ug/L /Boron/

(MN) MINNESOTA 1,000 ug/L /Boron/

(WI) WISCONSIN 960 ug/L /Boron/

... /During inhalation exposures up to 6 months at concentrations of 12.8 ppm, 3-4 ppm and 1.5 ppm/ the average fluorine content of rat teeth and bone was elevated at all exposure levels but not in soft tissues analyzed, lung, liver and blood.

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]

Brazing [Category: Heat or Machine]

A catalyst in organic synthesis, boron trifluoride is used in soldering fluxes, for neutron measurement and as a fumigant. Boron trifluoride is also used to protect molten magnesium and its alloys from oxidation.

The most important uses are in organic syntheses. Boron trifluoride is commonly used as a catalyst for Friedel-Crafts alkylation reactions. It also is used to catalyze the cleavage of ethers to alcohols, to catalyze esterification reactions, and in the nitration and sulfonation of aromatic compounds. Many olefin polymerization reactions use BF3 as an initiator, in conjunction with a proton donor, such as water. Also BF3 is used to catalyze the isomerization of alkenes and alkanes and in petroleum cracking and desulfurization. Amine complexes of BF3 are used as epoxy curing agents.

To protect molten magnesium and its alloys from oxidation; as a flux for soldering magnesium; as a fumigant; in ionization chambers for the detection of weak neutrons.

Production of diborane, instruments for measuring neutron intensity, ... gas brazing.

Common impurities in BF3 include air, silicon tetrafluoride, and sulfur dioxide.

1.0% nitrogen; <0.006% sulfur dioxide; <0.0006% ferric oxide; <0.003% silicon dioxide; traces of oxygen.

Commercially, BF3 has been produced by the stepwise addition of hydrofluoric acid and sulfuric acid to anhydrous borax (sodium tetraborate).

From borax and hydrofluoric acid or from boric acid and ammonium bifluoride. The complex formed is then treated with cold-fuming sulfuric acid.

Preparation: Swinehart, US 2148514, US 2196907 (1939, 1940 both to Harshaw Chemical)

Wiesboeck, US 3690821 (1972 to U.S. Steel)

Boron trifluoride is made commercially in the United States by a proprietary process from boric acid and hydrofluoric acid.

Grades: Pure (99% min)

10% boron trifluoride in methanol

99.5% boron trifluoride hydrate; boron trifluoride dihydrate, 95%

Boron trifluoride is available in quantity as a 99% pure gas.

Borane, trifluoro-: ACTIVE

Lab preparation: decomposition of a diazonium fluoroborate and the fluorination of boron trichloride with antimony trifluoride

In the finished product, the content of decomposition products of the catalyst must not exceed 0.04% of boron & 0.3% of fluorine.