Animal toxicity studies with ammonium perfluorooctanoate

These studies were conducted to evaluate the potential toxicity of ammonium perfluorooctanoate, a commercial surfactant. They include acute and subchronic feeding studies with rabbits, mice, rats and monkeys as well as in vitro mutagenicity assays with Salmonella typhimurium and Saccharomyces cerevisiae. The compound was non-irritating to the skin and moderately irritating to the eyes of rabbits. The rat oral LD50 was 540 mg/kg; no deaths resulted from a one hour rat inhalation exposure at a nominal concentration of 18.6 mg/L. All in vitro assays were negative. The liver was the target organ in rodents in both the 28 day and 90 day feeding studies with males showing a greater response than females. Serum and liver concentrations of organic fluorine were greater in male than in female rats. In a 90 day oral study in rhesus monkeys the gastrointestinal tract and the reticuloendothelial system were the sites of toxic effects. The gastrointestinal effects were attributed to the potent surface activity of the compound. Histopathological effects wer noted in the spleen, lymph nodes and bone marrow. Unlike the rats, sex related differences were not evident in the monkeys. Toxicological evaluations of ammonium perfluorooctanoate are continuing.