Acute, subacute and chronic toxicity of fosfosal

Acute, subacute and chronic toxicity studies of 2-phosphonoxy benzoic acid (fofosal) were carried out in several animal species. LD50 values in mice and rats were determined at two pH values; an additional toxic effect of acidity was found at the lowest pH tested (pH = 1.0), specially so by i.p. route. Differences in LD5- values between mice and rats of either sex were not significant; however, acute toxicity of male rabbits was higher than that of rats and mice. Long-term toxicity studies revealed a slight growth retardation and a significant mortality at the highest dose tested (500 mg/kg). These studies showed that fosfosal produced no hematological, blood chemical or pathological changes.