Boron Trifluoride


Boron trifluoride gas is corrosive to exposed tissues and to the upper and lower respiratory tracts. The gas penetrates deeply into body tissues and will continue to exert toxic effects unless neutralized.

Boron trifluoride decomposes to hydrofluoric acid in the presence of moisture, particularly in elevated temperature conditions. Exposures should be treated similarly to those of hydrofluoric acid. Workers should have 2.5% calcium gluconate gel on hand before work with boron trifluoride begins.

Emergency Procedures

Skin Contact: Boron Trifluoride hydrolyzes very rapidly yielding hydrofluoric acid so that skin burns are like that from exposure to HF. Flush affected area with copious amounts of water for 5 minutes. Remove contaminated clothing as rapidly as possible. Apply 2.5% calcium gluconate gel to the affected area and continue to apply every 15 minutes while seeking immediate medical attention.

Eye Contact: Eye contact will cause severe irritation and inflammation. Painful burns may result in lesions and loss of vision. Persons with potential exposure to boron trifluoride should not wear contact lenses. Flush contaminated eye(s) immediately with copious quantities of water. Continue for a minimum of 30 minutes. Seek medical attention immediately.

Inhalation: Even very low concentrations may irritate the respiratory tract and brief exposure to 50 ppm can cause cardiac collapse, pulmonary edema and chemical pneumonitis. High concentrations can cause severe damage to the respiratory system and can be fatal. PROMPT MEDICAL ATTENTION IS NECESSARY IN ALL CASES OF OVEREXPOSURE. Conscious persons should be assisted to an area with fresh, uncontaminated air.

Ingestion: Not a likely route of exposure.


Dry Boron Trifluoride may be used with mild steel, copper, copper-zInc. and copper-silicon alloys, nickel or Monel. The moist (water) gas is best handled in Monel. Fluoride "passivation" is also recommended. Kel-F and Teflon are the preferred gasketing materials. Many of the metal fluorides are water soluble so that the passive film corrosion protection may be destroyed if wetted with water. Use only in well-ventilated areas, vented gas storage cabinets, or fume hoods. Process valves should be opened and closed with remote controlled extensions passing through a suitable barricade for additional protection. Double valving should be employed to facilitate the reduction in pressure from high pressure sources of boron trifluoride.

Boron trifluoride reacts with many materials normally recommended for handling compressed gases. Thoroughly review the incompatibilities before working with this substance.


Use and store boron trifluoride in a ventilated gas cabinet or fume hood. When a gas cabinet is warranted (e.g., cylinders larger than lecture bottle size that are used in a fume hood), install a toxic gas monitoring system. Follow all applicable recommendations for storage and handling of compressed gases.


Boron trifluoride cylinders should be returned to the compressed gas distributor when emptied or no longer

Section 10 Chemical List