Rat and rabbit oral developmental toxicology studies with two perfluorinated compounds

Developmental toxicology (teratology) studies were done on two perfluorinated compounds-perfluorooctanesulfonate (PFOS) and 2-(N-ethylperfluorooctanesulfonamido)ethyl alcohol (N-EtFOSE) in rats and rabbits. Dose selection for these oral developmental toxicity studies were based upon dose-range study results. Dose levels of 0, 1, 5, 10, and 20 mg/kg/day were used for the rat N-EtFOSE study, and dose levels of 0, 0.1, 1.0, 2.5, and 3.75 mg/kg/day were used for both the PFOS and the N-EtFOSE rabbit studies. Although no compound-related deaths occurred in the dosed pregnant females on the developmental toxicity studies, maternal toxicity (reduced body weight gain and feed consumption) was present at higher dose levels in all three studies. At high maternally toxic doses, associated effects occurred in the conceptuses--increased abortions in PFOS and N-EtFOSE rabbits, reduced fetal weights in N-EtFOSE rats and PFOS rabbits, and increased late resorptions in N-EtFOSE rabbits. Detailed external gross, soft tissue, and skeletal fetal examinations failed to reveal any compound-related malformations in either species. Similar results, that is, only effects associated with maternal toxicity, had been found in previously conducted PFOS rat developmental toxicity studies. It was concluded that these perfluorinated compounds were not selective developmental toxicants in either rats or rabbits.