A Critical Review of Scientific Data Pertaining to Dermal Exposures to Per- and Polyfluoroalkyl Substances (PFAS)

Per- and polyfluoroalkyl substances (PFAS) are synthetic highly fluorinated organic compounds that have been used in a variety of industries and commercial and consumer products such as non-stick cookware, food packaging, medical devices, textiles, firefighting foam, and cosmetics and personal care products (PCPs). Due to concerns regarding the environmental and human health risk of PFAS, numerous studies have been published that investigated topics such as environmental fate, oral toxicology, and potential exposure pathways and routes. Few studies have characterized dermal exposure and uptake potential of PFAS, despite recognition that dermal contact may represent a viable exposure route in certain scenarios. This analysis includes a targeted literature review of studies evaluating PFAS dermal exposure potential, including (1) the potential for transfer and loading onto the skin surface as a result of common dermal exposure pathways, (2) empirical data regarding dermal exposure assessment factors, and (3) estimates of external dermal doses associated with different PFAS exposure sources in addition to any internal dose estimates. Across 37 relevant studies identified, 18 evaluated PFAS exposure from use of cosmetics and PCPs, eight from clothing, six from dust, and five from other scenarios (e.g., site contamination, electronic waste). Estimates for human dermal exposure were generally <1 ng/kg-bw/day for individual compounds and total PFAS, although some authors reported >100 ng/kg-bw/day for select scenarios. Studies generally reported that dermal PFAS exposures, when measurable, constituted a small fraction of total PFAS exposure relative to other routes. The toxicological relevance of dermal PFAS exposures at these levels remains unclear.