Per- and Poly-fluorinated alkyl substances (PFAS), have been used in many industrial applications (e.g., non-stick coating) as a chemically and thermally stable compound. However, these compounds have known human health impacts, and thus have been largely phased out. Nonetheless, PFAS compounds are still detected in air and water, and there exists a data gap in our understanding of the chemical degradation and environmental fate of PFAS compounds. This work will perform laboratory experiments in order to fill this data gap and improve out understanding of PFAS chemistry – with a focus on perfluorooctanoic acid (PFOA) – and the likely impact of PFAS compounds on the environment and human health.<br/><br/>This proposed work has three primary research goals: (1) to quantify the thermodynamic properties relevant for atmospheric phase partitioning of PFAS and PFAS-replacing chemicals; (2) to estimate the atmospheric lifetime of these chemicals against OH chemistry; and (3) to investigate reaction mechanisms of these chemicals. Additionally, this proposed work has an educational objective to establish an exchange to enable undergraduate students to broaden their educational experience by conducting summer research among the collaborative institutions. This proposed work will conduct three primary tasks to reach these objectives. First, the team will quantify the thermodynamic properties – namely saturation vapor pressure, Henry volatility, and acid dissociation constants – that influence the phase partitioning of PFAS. Second, they will conduct multiple oxidation flow reactor experiments to constrain the impact of OH radical chemistry on PFAS. Third, they will estimate rate constants of PFAS against OH and develop potential reaction mechanisms.<br/><br/>This project supports one postdoctoral researcher.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.