Absorption, distribution, and excretion of ammonium perfluorooctanoate (APFO) after oral administration to various species.

Male and female mice, rats, hamsters, and rabbits were treated with a single oral dose of 14C-ammonium perfluorooctanoate (APFO), and the excretion and tissue distributions were followed for 120 h (168 h in the rabbit). Substantial sex and species differences in the excretion and disposition of 14C-radioactivity derived from 14C-labeled APFO were observed in this study. The female rat and the male hamster excreted more than 99% of the original 14C activity by 120 h after dosing; conversely, the male rat and the female hamster excreted only 39% and 60% of the original 14C activity, respectively, by 120 h postdosing. The male and female rabbits excreted the 14C activity as rapidly and completely as the female rat and the male hamster, whereas male and female mice excreted only 21% of the original 14C activity by 120 h postdosing. The rapid excretors (female rat, male hamster, and male and female rabbits) contained negligible amounts of 14C in organs and tissues at sacrifice. The slow excretors exhibited the highest 14C concentrations in the blood and liver followed by the kidneys, lungs, and skin.