Systemic toxicity induced by topical application of the sulfonic acids, perfluorobutane sulfonic acid (PFBS) and perfluoropentane sulfonic acid (PFPeS), in a murine model.

Per- and polyfluoroalkyl substances (PFAS) are a large group of synthetic surfactants incorporated into products for their chemical and physical properties. Studies have associated PFAS with adverse health effects. Although there is a high potential for dermal exposure, toxicity studies related to this route of exposure are lacking. The present study evaluated the systemic toxicity following a sub-chronic 28-day dermal exposure to perfluorobutane sulfonic acid (PFBS) (1.25-5 %) or perfluoropentane sulfonic acid (PFPeS) (1.25-5 %) in a murine model. Elevated levels of both PFAS were detected in the serum and urine, suggesting that absorption occurs through the skin. Additionally, both PFAS induced significantly increased relative liver weight, altered serum chemistries, altered skin and liver histopathology, and significantly decreased relative spleen weight (PFPeS only). Gene expression changes were observed in the liver and skin for genes involved in fatty acid metabolism, inflammation, and skin integrity. In general, the PFPeS-induced changes in the endpoints examined were observed more frequently compared to PFBS, supporting the concept that longer-chain PFAS are more toxic. These findings support PFAS absorption through the skin, leading to liver damage and systemic toxicity.