Popular smartwatch straps contain high levels of harmful PFAS chemicals that may cause cancer

A recent Environmental Science & Technology Letters study uncovered worrying amounts of potentially harmful chemicals in smartwatch straps from major brands. The researchers examined 22 watch bands from well-known names like Apple, Samsung, Google, and Fitbit.

They discovered that nine of the bands tested had high amounts of perfluorohexanoic acid (PFHxA), a type of PFAS chemical. In some cases, the levels shot up past 1,000 parts per billion—far higher than what’s usually seen in everyday products.

PFAS chemicals like PFHxA are often referred to as "forever chemicals" because they persist in the environment and human body for long periods. Alarmingly, some PFAS have been linked to health issues, including an increased risk of cancer, according to studies conducted over the past decade.

Graham Peaslee, a co-author of the study and professor emeritus at Notre Dame, pointed out that these findings are especially concerning because of the constant skin contact people have with these wearables.

Although the study didn’t mention specific manufacturers in its results, Apple has stated that its Regulated Substances Specification caps PFHxA levels at 25 ppb for the compound and its salts and 1,000 ppb for related substances.

On the flip side, toxicology experts like Jamie Alan from Michigan State University note that the study's testing methods don’t perfectly mimic real-life conditions. This means the amount of PFHxA your skin actually absorbs might be pretty low. Even so, the researchers suggest switching to non-fluoroastomer straps as a safer bet to cut down on exposure.