<b>Aqueous secondary formation substantially contributes to hydrophilic organophosphate esters in aerosol</b><b>s</b>

We combine field measurements and partitioning models to reveal that OPEs could be enhanced by aqueous-phase processes in aerosols. We suggest that dissolved inorganic salts and transition metals in aerosols positively impact on the formation of hydrophilic OPEs, by facilitating aqueous partitioning and/or oxidation. The dataset includes mean concentration and contribution of OPEs, the results related to the partitioning behavior of OPEs, secondary formation tracers and the PMF results reported in the study.