Implications of PFAS definitions using fluorinated pharmaceuticals.

There are 9,000+ per- and polyfluoroalkyl substances (PFAS) in existence, which makes studying and regulating PFAS individually, or even as small mixtures, infeasible. Multiple PFAS definitions based on structure have been proposed, yet these definitions do not consider the implications for the full suite of organofluorine chemicals. For example, organofluorine pharmaceuticals, whose use may be essential and are found in human serum and wastewater, are not uniformly identified across all definitions.