Per- and polyfluoroalkyl substances (PFASs) comprise a class of chemicals that has attracted much attention since the early 2000s, when the hazards and ubiquitous occurrence of two PFASs─perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS)─were reported. Early communications used multiple terms such as “per- and polyfluorinated chemicals”, “perfluorinated organics”, “perfluorochemical surfactants”, and “highly fluorinated compounds”. In 2011, to harmonize communication, Buck et al. (1) published a milestone paper, providing the first clear structural definition of PFASs and recommendations on the names and acronyms for over 200 individual PFASs. Since then, research and regulation has expanded from PFOA and PFOS to a much wider range of substances.