Perfluorinated surfactants such as N-methyl perfluorooctane sulfonamidoethanol (NMeFOSE) are produced for a large number of applications such as fire fighting foams and furniture coatings. These chemicals are emerging as an important class of environmentally persistent chemicals. Our knowledge of their metabolism, distribution, disposition and, ultimately, mechanisms of toxicity is very limited. Exposure to these chemicals has been associated with developmental toxicity in several animal models. This research hypothesizes is that after uptake with the diet, NMeFOSE is metabolized in vivo to perfluorooctane sulfonic acid. Studies aims are (1) to synthesize putative perfluorooctane sulfonyl metabolites (2) establish analytical assays to measure NMeFOSE and its metabolites in biological samples, (3) study the in vitro metabolism of NMeFOSE with rat liver microsomes, and (4) measure the distribution of NMeFOSE and its metabolites in female rats.