Elevated levels of 'forever chemicals' found in smartwatch bands – here's what you need to know

(Image credit: Future / Matt Evans)

Scientists have tested the level of PFAS in some consumer smartwatch bands
They found elevated levels of "forever chemicals" in some models
These chemicals are potentially toxic and have been linked to diseases such as cancer

Scientists from the University of Notre Dame have called for more comprehensive studies and greater transparency from manufacturers after a study found elevated levels of so-called "forever chemicals" in some consumer smartwatch and fitness tracker bands.

The study, published this week in Environmental Science & Technology Letters, analyzed 22 watch bands from numerous brands and price points and found that some of these bands contained elevated levels of PFAS (polyfluoroalkyl substances), namely perfluorohexanoic acid (PFHxA). These chemicals are colloquially known as "forever chemicals" because they have an almost unbreakable chemical structure which means they don't degrade or break down over time.

The tested brands include many of the best smartwatch manufacturers and accessory makers including Apple (and Apple Watch Nike sport bands), CASETiFY, Fitbit, Google, and Samsung.

PFAs in smartwatch bands, should you be worried?

Fitbit Inspire 2 — (Image credit: Future)

"This discovery stands out because of the very high concentrations of one type of forever chemical found in items that are in prolonged contact with our skin," Peaslee told Independent. "We have never seen extractable concentrations in the part-per-million range for any wearable consumer product applied to the skin," he warned. The study's lead author, Alyssa Wicks, recommends buying lower-cost silicone bands, or avoiding products listed as containing fluoroelastomers if they want a more expensive band.

While the study does mention some big names in the smartwatch sector, notably Apple, Samsung, and Google, it's difficult to extrapolate too much because the study doesn't give the results for each brand. Companies like Apple clearly advertise Fluoroelastomer as present in its best Apple Watch bands, notably its Nike offerings, Sport Band, and the Apple Watch Ultra's Ocean band. However, the study doesn't tell us which of the bands offered by these major players were tested, or if they were the bands with notably high PFA levels.

Samsung and CASETiFY were not immediately available to comment on the story. Apple pointed TechRadar to its work on testing materials and its commitment to totally phasing out PFAS from its products and manufacturing processes from 2022.

More specifically, Apple also highlighted its Regulated Substances Specification document, which specifically lists PFHxA, the offending chemical highlighted in the study, as a restricted substance. Apple says that for PFHxA, its salts and related substances, it has a threshold limit of "25 ppb for the sum of PFHxA and its salts" and "1000 ppb for the sum of PFHxA-related substances."

"Don't panic"

As Wicks notes, there are also "few studies" on the absorption of PFAS through the skin. She cites one such article that found that a couple of types of PFAS had "significant transfer through the skin", but that it was a limited study that only examined 20 of the 14,000 known types of PFAS.

Speaking to Yahoo Life, Jamie Alan, associate professor of pharmacology and toxicology at Michigan State University called the findings "interesting", but said that the study doesn't give any insight into how much PFHxA is absorbed through the skin, if any is absorbed at all. Other specialists in toxicology and dermatology agreed, stating that it is unlikely a significant amount of PXHxA would be absorbed through the skin. Finally, Alan pointed out that the study involved chemically extracting these compounds from Apple Watch bands, something users aren't doing when they wear these items day-to-day. "So although they found very high levels, that does not mean any significant amount is getting into our system," she concluded.

Alan said there's no need to panic if you own a smartwatch or fitness tracker band with fluoroelastomer, but that "it is good to be aware of cumulative exposure." If you're looking for a new band, you could always choose a PFAS-free option.

Stephen Warwick is TechRadar's Fitness & Wearables writer with nearly a decade of experience covering technology, including five years as the News Editor of iMore. He's a keen fitness enthusiast and is never far from the local gym, Apple Watch at the ready, to record his latest workout. Stephen has experience writing about every facet of technology including products, services, hardware, and software. He's covered breaking news and developing stories regarding supply chains, patents and litigation, competition, politics and lobbying, the environment, and more. He's conducted interviews with industry experts in a range of fields including finance, litigation, security, and more. Outside of work, he's a massive tech and history buff with a passion for Rome Total War, reading, and music.