Many smartwatch and fitness-tracker bands do contain PFAS, and the ones most likely to are bands made of fluoroelastomer, a sweat-resistant synthetic rubber. In a 2024 University of Notre Dame study of 22 bands, the fluorinated compound PFHxA turned up most often in the fluoroelastomer bands, while silicone bands had little to no detectable PFAS. If you want the simplest safer choice, wear a plain silicone band and skip any band advertised as fluoroelastomer.
The study came out of the lab of Graham Peaslee at the University of Notre Dame and was published in the journal Environmental Science & Technology Letters in late 2024. The team screened 22 watch bands for fluorine, then tested for specific PFAS. A few findings stand out, as Notre Dame reported:
The honest answer is that the exposure question is not settled. The concern is skin contact, because a watch band sits against your wrist for hours. Peaslee's team called for more research on how much PFHxA can actually move through skin, and said that is the open question, not whether the chemical is present. So treat this as a reason to choose a cleaner band, not a reason to panic about past wear.
The band is one of several everyday products where PFAS show up in a stain- or sweat-resistant finish. The same pattern appears in leggings and activewear and in cosmetics and makeup, so it is worth knowing where the chemistry tends to hide.
The researchers' own advice, reported by Futurity, is direct: choose silicone instead of fluoroelastomer, because silicone bands tested clean. When you shop, read the product description and avoid anything listed as fluoroelastomer or "fluoro" rubber. Plain silicone, nylon or woven fabric, leather, and metal bands are all alternatives that avoid the fluoroelastomer problem.
Silicone replacement bands are inexpensive and fit almost every popular watch:
Which watch bands have the most PFAS? In the Notre Dame testing, fluoroelastomer bands carried the highest PFHxA levels, and higher-priced bands tended to be worse than cheap ones.
Do Apple Watch and Fitbit bands have PFAS? The study tested bands across brands rather than naming a verdict for every model. The reliable signal is the material: if a band is fluoroelastomer, assume it may contain PFAS, and if it is plain silicone, it tested clean in this research.
Is it dangerous to wear one now? The study showed PFAS are present but did not establish how much crosses the skin. If you want to reduce exposure, switching to a silicone band is a cheap, low-effort step.
Are silicone watch bands really PFAS-free? In the Notre Dame testing, silicone bands had little to no detectable PFAS, which is why the researchers recommended them. Silicone is a different polymer family than the fluoroelastomer that carried the high PFHxA levels.
Educational information, not medical advice. Know Your Exposure accepts no payment from any product brand; some links are affiliate links that never change what we recommend.