Hydrofluoric Acid


💊 Chemical information

Fluohydric Acid; Fluorhídrico, ácido; Fluoric Acid; Kwas fluorowodorowy.
HF = 20.01.
CAS — 7664-39-3.


Hydrofluoric acid is a solution of hydrogen fluoride in water. Various strengths are used. It attacks glass strongly.

💊 Adverse Effects

As for Hydrochloric Acid, above. Although the corrosive effects of hydrofluoric acid tend to predominate, absorption may produce systemic fluoride poisoning as described under Sodium Fluoride. The pain from contact with weak solutions may be delayed, so that the patient is not aware of being burnt until some hours later, when the area begins to smart; intense pain then sets in and this may persist for several days. Destruction of tissue proceeds under the toughened coagulated skin, so that the ulcers extend deeply, heal slowly, and leave a scar. The fumes of hydrofluoric acid are highly irritant.

💊 Treatment of Adverse Effects

The initial treatment of poisoning after oral exposure to hydrofluoric acid is similar to that described for hydrochloric acid, see above. Calcium gluconate should also be given intravenously to correct known or suspected hypocalcaemia. Burns in the eye are also managed as for hydrochloric acid, although irrigation of the eye may be continued with calcium gluconate solution 2% after initial flood with water or sodium chloride 0.9%. In the event of skin burns with hydrofluoric acid, contaminated clothing or articles should be removed and the skin washed with copious cold water. A calcium gluconate gel is sometimes used and it may be necessary to infiltrate the affected areas with calcium gluconate intradermally or subcutaneously. Regional intravenous infusion of calcium gluconate may be necessary in severe burns of the forearm, hand, or fingers; if ineffective, intra-arterial infusion for burns of the fingers may be considered. Hydrofluoric acid passes through finger- and toe-nails without causing any apparent damage; nails will therefore have to be removed or perforated to be able to treat the underlying tissues. Other first-aid measures reported to be effective include prolonged soaks in iced solutions of benzalkonium chloride; iced water has sometimes been used as has iced magnesium sulfate solution. Local anaesthesia may be needed. Burn eschars should be excised and necrotic tissue debrided. Absorption may lead to systemic fluoride toxicity and the need for intravenous calcium gluconate to manage hypocalcaemic symptoms.
1. Browne TD. The treatment of hydrofluoric acid burns. J Soc Occup Med 1974; 24: 80–9
2. MacKinnon MA. Hydrofluoric acid burns. Dermatol Clin 1988; 6: 67–74
3. McIvor ME. Acute fluoride toxicity: pathophysiology and management. Drug Safety 1990; 5; 79–85
4. Kirkpatrick JJR, et al. Hydrofluoric acid burns: a review. Burns 1995; 21: 483–93
5. Sanz-Gallen P, et al. Hypocalcaemia and hypomagnesaemia due to hydrofluoric acid. Occup Med (Lond) 2001; 51: 294–5
6. Martin HCO, Muller MJ. Hydrofluoric acid burns from a household rust remover. Med J Aust 2002; 176: 296
7. Foster KN, et al. Hydrofluoric acid burn resulting from ignition of gas from a compressed air duster. J Burn Care Rehabil 2003; 24: 234–8.

💊 Uses

Hydrofluoric acid is used in industry. Its main use has been for the production of fluorocarbons for use as refrigerants and propellants. It has also been used as an ingredient of preparations for glass etching and rust removal.


Hydrofluoric acid has been used in homoeopathic medicines under the following names: Fluoricum acidum; Acidum hydrofluoricum; Ac. fluor.
Published May 08, 2019.