What Is Hydrofluoric Acid?

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  • What Is Hydrofluoric Acid?

1. Hydrofluoric Acid(HF)

  • Hydrofluoric acid is a highly corrosive solution of the chemical compound hydrogen fluoride in water.
  • It is extremely hazardous as it can penetrate human skin, allowing it to destroy soft tissues and decalcify bones

2. Industrial applications of HF

  • It is used mainly for industrial purposes, for example, glass etching, metal cleaning, electronics & semiconductor manufacturing, and so
         on.
  • Anhydrous HF is considered to be pure hydrogen fluoride. It is a water-free vapor of hydrofluoric acid; used in conjunction with vapor of
         either water or alcoholic solvents (e.g. methanol) to etch silicon oxides on the wafer surface as well as dry etching.
  • Aqueous HF is a water solution of hydrogen fluoride. It is mainly used in glass etching, glass slimming, metal cleaning/processing and      quartz purification
  • As Semi-conductor and display industries increase, HF accidents also increase.

3. Symptom after HF exposure

  • 1With regard to human toxicity, HF is of particular concern because not only does its contact with skin cause local burns, but the Fluoride
         ions readily penetrate the skin to cause systemic poisoning.
  • Skin penetration by HF is retarded by the lipid layer of intact skin and accelerated by abrasions or minor trauma. Death can occur from a
         splash of as little as 2.5% of the body surface with concentrated HF.
  • Inhaling HF vapors (boiling point 68F) leads to pulmonary edema, and in high enough concentrations, death.
  • Fluoride ions that penetrate the skin into systemic circulation bind to divalent cations, primarily calcium and magnesium, leading to
         electrolyte imbalance, cardiac arrhythmia, and death.
  • Fluoride also inhibits glycolysis and oxidative phosphorylation with the same results.
  • 6Contact with HF in concentrations less than 50% does not cause immediate pain, so systemic poisoning can begin before the person is
         aware they have had contact with the acid.


  • Symptom after anhydrous HF inhalation


  • Example of hip fracture


  • Symptom of hydrous HF skin exposure