Fluoride Action Network


The acute toxicity of hydrofluoric acid (HFA) was investigated in a 24-hour lethal dose study of intravenous injection in rats. The LD50 and LD90 were 17.4 and 23.0 mg/kg, respectively. Harmful systemic effects were also studied 1 hour after acute sublethal exposure to HFA. Rats were injected with HFA (1.6, 3.2, 6.4, or 9.6(LD5) mg/kg) or saline. Blood samples were obtained from the carotid artery. BUN and Cr were significantly increased in response to HFA concentrations greater than 3.2 mg/kg. Acute glomerular dysfunction also occurred at HFA concentrations greater than 3.2 mg/kg. PCO2, HCO3 and base excess were significantly decreased in the 6.4 and 9.6 mg/kg groups. Total and ionized calcium was significantly decreased, and potassium was increased in the 9.6 mg/kg group. Ionized fluoride exposure directly affected serum electrolytes. Mortality was thought to be due to cardiac arrhythmia resulting from hypocalcemia and hyperkalemia. Metabolic acidosis and renal failure were severe in response to HFA exposure. Even low exposure to HFA can cause acute renal dysfunction, electrolyte abnormalities and metabolic acidosis. These complications result in a poor prognosis.