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 PFBS (1.25-5%) or PFPeS (1.25-5%) in a murine model. Elevated levels of both PFAS were detected in the serum and urine, suggesting that absorption is occurring through the dermal route. Additionally, both PFAS induced significantly increased relative liver weight, altered serum chemistries, altered skin and liver histopathology, and significantly decreased relative spleen (PFPeS). Gene expression changes were observed in the liver and skin, of genes involved in fatty acid metabolism, inflammation, and skin integrity. In general, the toxicity was more dramatic for PFPeS compared to PFBS, suggesting that longer chain PFAS may be more toxic. These findings support PFAS absorption through the skin leading to liver damage and systemic toxicity.