Presence of\nPerfluorohexanoic Acid in Fluoroelastomer\nWatch Bands

Many “smart” and “fitness”\nwatch bands\nare advertised to contain fluoroelastomers, a type of synthetic rubber\ndesigned to be resilient against skin oils and sweat. Fluoroelastomers,\nwhich are considered a polymeric form of per- and polyfluoroalkyl\nsubstances (PFAS), have historically involved the use of shorter-chain\nPFAS as surfactants in the polymerization process. In this study,\n22 watch bands were analyzed across numerous brands and price points\nfor the presence of PFAS. Products were first screened for total fluorine\nusing particle-induced gamma-ray emission spectroscopy on the surface\nof these bands, and 15 of the 22 watch bands contained total F concentrations\n>1% fluorine, suggesting the widespread use of fluoroelastomers\nin\nthis product category. Watch bands then underwent solvent extraction\nand targeted LC-MS/MS analysis for 20 PFAS. Perfluorohexanoic acid\n(PFHxA) was the most frequently detected compound with concentrations\nfrom