Smartwatches and fitness trackers might pose health risks due to high levels of PFHxA, a chemical found in the fluorinated rubber used in premium wristbands. These findings highlight potential skin exposure concerns from daily wearable tech.
Smartwatches and fitness trackers have become everyday essentials, worn by many people around the clock. However, new research suggests that these devices may expose wearers to harmful “forever chemicals.” A study published today (December 18) in ACS Environmental Science & Technology Letters found that pricier wristbands made from fluorinated synthetic rubber contained notably high levels of perfluorohexanoic acid (PFHxA), a type of forever chemical linked to environmental and health concerns.
Study Highlights High Levels of PFHxA
“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,” explains Graham Peaslee, the corresponding author of the study.
Per- and polyfluoroalkyl substances (PFAS) are a group of chemicals that are very good at two things — lasting seemingly forever in the environment and repelling water, sweat, and oil. Because of the latter properties, manufacturers include these chemicals in many consumer products, such as stain-resistant bedding, menstrual products and fitness wear, including smartwatch and fitness tracker wristbands.
The bands contain fluoroelastomers, synthetic rubbers made from chains of PFAS, to create a material that avoids discoloration and repels dirt. Though this durability makes the bands great for sweaty workouts, it might also present a source of these compounds to get under the wearer’s skin — literally. So, Peaslee and co-authors Alyssa Wicks and Heather Whitehead investigated several commercially available watchbands for the presence of fluorine as well as 20 individual PFAS.
Detailed Examination of Wristbands
The team screened 22 wristbands from a range of brands and price points, most of them newly purchased but a few previously worn. All of the 13 bands advertised as being made from fluoroelastomers contained the element fluorine. But two of the nine bands that did not advertise being made from fluoroelastomers also contained fluorine, which indicates the potential presence of PFAS. Of those tested, wristbands that cost more than $30 contained more fluorine than those under $15.
Next, following a chemical extraction, all the wristbands were checked for 20 different PFAS. PFHxA was found to be the most common, appearing in nine of 22 tested wristbands. The median PFHxA concentration was found to be nearly 800 parts per billion (ppb), and one sample exceeded 16,000 ppb. Comparatively, previous research by the team in 2023 on cosmetics found a median concentration of around 200 ppb of PFAS. Currently, only six PFAS have federally defined exposure limits for drinking water in the U.S.; exposure limits for other PFAS and other exposure routes are still being studied.
Health Implications and Recommendations
“We have never seen extractable concentrations in the part-per-million range (>1000 ppb) for any wearable consumer product applied to the skin,” says Peaslee.
The researchers suggest that the large amounts of PFHxA found in the wristbands may be a result of the compound being used as a surfactant during the fluoroelastomer manufacturing process. Scientists do not currently understand how readily PFHxA transfers into the skin, nor the potential health effects it poses once it gets there, though Peaslee says recent studies suggest that a significant percentage could pass through human skin under normal conditions.
Wicks, the study’s lead author, says the team recommends purchasing lower-cost wristbands made from silicone. “If the consumer wishes to purchase a higher-priced band, we suggest that they read the product descriptions and avoid any that are listed as containing fluoroelastomers.”
Reference: “Presence of Perfluorohexanoic Acid in Fluoroelastomer Watch Bands” by Alyssa Wicks, Heather D. Whitehead and Graham F. Peaslee, 18 December 2024, Environmental Science & Technology Letters.
DOI: 10.1021/acs.estlett.4c00907
The authors acknowledge funding from the University of Notre Dame.
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4 Comments
Well of course they do. They’re in practically everything. Not a shock. Not a problem. No story.
Not a shock, but it is a problem, and it is a story. Humans are not progressing or evolving if they have to absolutely destroy their home to keep themselves in things that well, perhaps they do not even need, It is a sad state, and frankly, if I could change my lifestyle to avoid needing items that contain forever chemicals, I would do it. I am trying, and the more I find out about these chemicals and other things that impact our planet, the more I work to avoid taking part.
This is going to be especially shocking for all of the people that like to eat their wristbands.
And the presence in menstral products aren’t concerning? Just on wristbands? Those are arguably different types of skin that would have different absorption properties. Would the skin against menstral products not absorb more? And children and elderly on waterproof bedding– their skin in more fragile that an adults.