Perfluorooctane Sulfonate (PFOS)

Like perfluorooctanesulfonic acid (PFOA), the per-and polyfluoro alkyl compound perfluorooctanesulfonate (PFOS) has seen widespread use in several consumer goods and industrial products and has emerged as an environmentally persistent pollutant. This section evaluates PFOS toxicity and the associated Toxicity reference Value (TRV) derivations. In reproductive rat models, significantly decreased bodyweights and decreased offspring survival were seen following exposure to PFOS. Benchmark dose analyses gave TRV-h (0.0521 and 0.098 mg/kg/d) and TRV-low (0.0327 and 0.068 mg/kg/d) values for male and female rats, respectively. In birds, a TRV-high of 0.64 mg/kg/d and a TRV-low of 0.15 mg/kg/d were derived from chronic oral reproductive studies in the mallard. Selected TRVs were also derived for amphibians from sub-chronic exposures. Mortality data gave a TRV-high of 0.075 mg/L/d and a TRV-low of 0.003 mg/L/d. Insufficient data precluded the development of TRVs for reptiles, which identifies an important research goal for PFOS and its derivatives for reptiles, and an urgent need for detailed chronic PFOS exposure studies on birds, amphibians, and reptiles.