Per- and polyfluoroalkyl substances (PFAS) in solar photovoltaic modules

Abstract

The presence of Per- and Poly Fluoro Alkyl Substances (PFAS) in solar modules is a growing concern, yet the current literature leaves key questions unanswered: Are PFAS present in solar modules? If yes, what types and quantities are involved, and what risks do they pose? This study attempted to address these gaps through a systematic review of the literature published over the past decade, focusing on five key areas: 1) the occurrence of PFAS in solar modules, 2) quantities in different solar module components, 3) suitable analytical methods for PFAS detection in solar modules, 4) United States Environmental Protection Agency PFAS's regulations and policies, and 5) screening levels and health risk assessments for PFAS in solar modules. Our findings highlight a paucity of data regarding PFAS in solar modules, with most references limited to their use in anti-reflective and self-cleaning coatings on solar glass and as barrier layer in backsheets. The literature provides some context for PFAS application in solar modules; however, information regarding PFAS types, amounts, layer thickness, and host component characteristics is lacking. While some laboratory studies explore hydrophobic PFAS coatings, they appear absent from commercial solar modules. Most PFAS used in solar modules are fluoropolymers, considered a low-risk PFAS subgroup. Currently, no standardized methods exist for PFAS analysis in electronics. Point-based health risk assessment in this work indicates no risk for PFOA, PFNA, PFOS, PFBS, or GenX for solar modules. Advancing quantification techniques for PFAS in solid matrices could enhance analysis capabilities and inform waste characterization strategies for the emerging solar waste stream.