To provide an overview of the environmental phase partition properties of neutral PFAS, a chemical space plot was generated following the approach in the literature (Figure ). The figure plots log Kaw against log Kow, both predicted by the PP-LFERs, and shows the equilibrium mass fractions of PFAS in a hypothetical system consisting of air, water, and organic solid (represented by octanol). The volume ratios of these phases were assumed to be 10 6 :10 3 :1, respectively, similar to those used in the cited reference. Note that interfacial adsorption was not considered here for simplicity and lack of parameters.