Using the PP-LFER solute descriptors for PFAS and the system parameters obtained above, values for Kow, Kaw, and Koa were calculated for the 47 neutral PFAS. Ideally, these predictions should be compared to external experimental data to validate the prediction accuracy. However, such data are not available. As an alternative approach, the predictions from the PP-LFERs were compared with those from COSMOtherm (Figure ). The root mean squared errors (RMSE) for log Kow, log Kaw, and log Koa were 0.37, 0.42, and 0.33, respectively, indicating high agreement.