Rationale of the treatment of hydrofluoric acid burns.

317-321. On contact with skin hydrofluoric acid yields hydrogen and fluoride ions, which exhaust the tissue's buffering capacity. Fluoride was found to be toxic to skin cells, as judged by the accumulation of 3-phosphoglycerate (3-PG), at about 2 × 10 mol/l fluoride ion in the medium on which skin slices were maintained. This toxicity was reversible by the dilution brought about by transfer of the skin to a fresh medium; 3-PG levels fell and tetrazolium reductase measurements showed adequate viability. Using a specific ion electrode for fluoride, the efficacy of calcium, magnesium and lanthanum salts and hyamine in lowering fluoride ion concentration in the presence of serum was examined. Lanthanum was the most effective but was itself toxic to skin cells as judged by respiration and tetrazolium reductase measurements. Calcium appeared more effective as chloride than as gluconate. Magnesium and hyamine were ineffective under the conditions of experiment. In the presence of serum, calcium gluconate is only just capable of lowering the concentration of fluoride ions to the level at which their toxic effect is negligible. The importance of rapid removal of hydrofluoric acid from the skin surface as a first-aid treatment is emphasized.