In a study published recently in the American Chemical Society’s Environmental Science & Technology Letters (and which Track Your PRs Without Extra Noise With the Best Basic Running Watches last week), researchers at the University of Notre Dame found that many smartwatch wrist bands contain very high amounts of perfluorohexanoic acid, or PFHxA. PFHxA is one of several forever chemicals, or per- and polyfluoroalkyl substances (PFAS), that do not naturally or easily break down over time. As we wrote, PFHxA “is commonly used in clothing, carpets, paper, and insecticides and has been linked to liver disease” and “PFHxA is an understudied PFAS compound because it is more difficult to detect in human blood than other PFAS.”
Brands use PFAS like PFHxA for the incredible resistance to water, sweat, and oil they can lend to different materials. This makes them particularly popular for waterproof items like rain jackets and umbrellas—as well as many fitness products. As a result, PFHxA is widely used in GPS watch and running watch bands. While the sweat-resistance is appealing, the study found that these watch bands can actually transfer the PFHxA from the band to the skin, where it could be absorbed into the body.
If you’re concerned, replace your current running watch wrist band with a new one that isn’t made with forever chemicals. I’ve laid out how you can go about making sure a band you’re considering is PFAS-free and recommended a few alternatives.
How to Tell Which Bands (Likely) Don’t Contain PFAS
Brands will often label a smartwatch wrist band with PFHxA as a “fluoroelastomer band,” which means it contains fluorine. The Notre Dame researchers observed that most of the fluorinated synthetic rubber wrist bands they studied had high levels of PFHxA. So, looking for that fluoroelastomer disclaimer is the easiest way to find out if a band you’re considering could contain PFAS. However, some bands aren’t labeled this way, instead called synthetic rubber or something similar. Two that the researchers studied that weren’t advertised as containing fluorine, in fact, did.
While the Notre Dame study doesn’t name specific brands, most major companies offer alternative wrist bands for watches that come with a band already attached. If you run with, say, a Garmin watch on your wrist, don’t worry; none of the brand’s watch bands contain PFHxA.
If you’re unsure, stick to something like silicone, which offers similar benefits to fluoroelastomer bands. The material is durable and resistant to water, sweat, and grease, too, without needing PFHxA.
While silicone is your best bet for PFHxA-free watch bands, here are some other common materials that are generally safe and widely available.
- Canvas: This lightweight material is breathable and comfortable while still being sturdy enough to handle adventures and workouts. While not fully waterproof, it’s fairly resistant to moisture and is a solid alternative for runners who don’t like the feel of silicone.
- Leather: A stylish (if not entirely practical) choice, leather wrist straps lend a classic feel. They are quite durable, though leather against sweaty skin may lead to chafing. It’s also not great at repelling water on its own.
- Metal: Metal wrist bands are incredibly durable and stand up well to the everyday wear and tear your smartwatch will go through. Depending on whom you ask, metal could be off limits for training. To us, it makes the most sense as a supplement to a silicone band. You can swap it on for work or formal occasions.
How to Tell If a Band Works With Your Watch
While I recommend a few options below, they won’t fit every smartwatch. Most of the brands offer smartwatch wrist bands for several different models and in many different sizes. So, if you like a certain band but don’t see it here for your watch, check the company’s Amazon page or website, because it’s likely that they’ll offer the same band for different watches and face sizes.
Most companies will list the specific models their bands are compatible with on the product page. If the band is a universal fit, look at the width of the wrist band attachment as your reference point. If that width of the connection point (which should be provided for you) is the same as your own watch’s, it should fit pretty well.
DAA Industry Opt Out
For anyone looking for a replacement wrist band for their smartwatch, I’ve listed a few options below. In choosing them, I first considered the available materials. While leather and metal are obvious choices, I left them out because they aren’t great for exercising. With that in mind, I prioritized silicone for its sweat- and water-resistance. The outlier is the Prime Day Centr Runr-S Sale, which I chose as a great alternative to silicone if you don’t like how the material feels against their wrist. It won’t have the same resistance to the elements that silicone has, but will feel a lot more comfortable.
I then researched brands that make their bands for a variety of watches and in a range of sizes. For universal wrist bands, the width determines which watch it fits with, so I looked for options that offer multiple widths. I also considered bands that are compatible with some of the more popular running watch brands.
Once I had those parameters, I looked closely at the durability of the bands, design choices, and customer reviews to gauge whether the bands would hold up well to vigorous exercise and everyday life alike while still being comfortable to wear.
For any Apple Watch wearers, this durable strap from Carterjett might be the last one you’ll ever need. The silicone material is thick enough and the tread texture rugged enough for daily wear and tear while also boasting the sweat- and water-resistance for active training. The textured interior leaves space for air to circulate around your wrist.
The thin silicone bands stand out not just for their extreme affordability, but also for the plethora of color options and the open, modern design. The already thin watch band means your wrist is still open and free while still rocking a full-size smartwatch. The thinness doesn't mean a lack of strength either as the metal buckle holds the strap firmly in place.
If you aren’t keen on silicone but still want a strap built for activity, this canvas band is a solid choice. Beyond the added comfort and breathability, the wrist band is also quite durable while offering some level of water-resistance. It has broad compatibility, too, with multiple size options allowing it to attach to several different smartwatches.
Tom Price is a Reviews Editor for Popular Mechanics and Runner's World Best Running Headphones Best Products and Bicycling. Prior to his work here, he previously covered product reviews, startup news, pop culture and even professional wrestling. In his free time, he enjoys watching pretentious TV, low-brow movies, and exercising for beauty, not health. If you are interested in exploring more of his work, check out his website.
