Hydrofluoric Acid Safety

Hydrofluoric acid (HF) is a clear, colorless liquid consisting of hydrogen fluoride gas dissolved in water. It is an extremely dangerous material and all forms, including vapors and solutions, can cause severe, slow-healing burns to tissue. At concentrations of less than 50%, the burns may not be felt immediately and at 20% the effects may not be noticed for several hours. At higher concentrations, the burning sensations will become noticeable much more quickly, in a matter of minutes or less. HF burns pose unique dangers distinct from other acids, as it readily penetrates skin, damaging underlying tissue. The fluoride ion can then cause destruction of soft tissues and decalcification of the bones by binding to the calcium in blood, bones, and other tissues.  Fluoride ions can reduce serum calcium levels, possibly causing fatal hypocalcemia. HF can cause severe burns to the eyes, which may lead to permanent damage and blindness. HF burns can be very painful and are often lethal. People have died from relatively small exposures to HF. The critical minutes immediately after exposure can greatly affect the chances of a victim’s survival. Calcium gluconate gel is commonly used to treat HF exposure and can be supplied to the laboratory by Environmental Health & Radiation Safety (EHRS). The 1% calcium gluconate solution or the 0.5% pontocaine hydrochloride solution for washing the eyes must be provided by the Principal Investigator.

HF is Incompatible with glass, ceramics, concrete, fluorine, some oxides, water-reactive materials, sulfuric acid, acetic anhydride, and alkali materials. It may generate flammable hydrogen gas on contact with metals. Toxic gases may be released on contact with carbonates, sulfides, and cyanides. Corrosive to leather, rubber, and many organics are also incompatible. Please avoid the use of the plastic PTFE, as it is slightly permeable to HF.

Some reactions may generate gas, which may produce pressure in the containers.  Containers have burst open due to the pressure build-up. Open carefully in a chemical fume hood. EHRS can supply laboratories with pressure relief caps upon request, but, at this time, only size 38/439, which should fit most standard 0.05 to 4L bottles. Please make sure the caps fit the selected containment vessel before its use. Do not use glass containers. Do not ingest. Do not breathe in gas, fumes, vapor, or spray. 

Work involving HF must be isolated and labeled. A copy of the HF chemical safety summary [PDF] and the safety data sheet (SDS) must be posted near the work area. Personnel must review the summary and SDS prior to performing any work involving HF. Appropriate attire and personnel protection equipment must be worn at all times when working with HF. 

The Principal Investigator must perform a risk assessment prior to allowing any individual to work with HF. Laboratory personnel must be trained on the hazards and risks associated with the process prior to initiating work. The risk assessment and training must be documented and uploaded to BioRAFT. 

Please contact EHRS if you have any questions or concerns.