Pfas are very resistant compounds, so much so that they are also known as “eternal chemical substances”: very poorly biodegradable, and capable of repelling water and fats with great efficiency. They have been used for decades to make pans and paints non-stick, as an anti-dust coating, in the production of cosmetics. But in recent years there have begun to be several doubts regarding their safety, given that they are capable of surviving practically indefinitely in the environment and tend to accumulate inside the human body, with effects that are still unclear.
As a precaution it would therefore be best to avoid them as much as possible. The problem, however, is that they are truly everywhere, even where you least expect them. A study by the University of Notre Dame reveals, for example, that smartwatches and fitness trackers contain extremely high quantities, and that they could therefore enter the bodies of millions of people who wear these devices daily through the skin.
Pfas on the wrist
As we were saying, Pfas (or per- and poly-fluoroalkyl substances) are used in many industrial fields due to their high properties of repelling water and fats. A feature that also makes them perfect for making smartwatch and fitness tracker straps more resistant to discoloration and dirt, as they are constantly exposed to mechanical stress and sweat, given that they are often used during physical exercise.
In their study, published in the journal ACS’Environmental Science & Technology Letters, researchers from the University of Notre Dame tested 22 devices of this type from different brands, and in different price ranges, to verify how widespread PFAS are in these products. The analyzes showed that all 13 devices with straps containing fluoroelastomers, a type of extremely resistant synthetic plastic made up of Pfas chains, had traces of fluorine, a clue to the presence of the “eternal chemicals”, which was also found in two of the nine products in which the use of fluoroelastomers was not reported by the manufacturers.
High-end products are more dangerous
Looking at prices, smartwatches and fitness trackers above $30 appear to contain, on average, higher amounts of fluoride. Among the PFAS analyzed, the most common was perfluorohexanoic acid (PFHxA), found in nine of the tested straps, with an average concentration of almost 800 parts per billion (ppb), which in one sample exceeded 16,000 ppb . Extremely high levels, if you consider that in their previous study the same scientists had analyzed the world of cosmetics, finding maximum concentrations of Pfas not exceeding 200 parts per billion.
“This discovery is exceptional – comments Graham Peaslee, a physicist at the University of Notre Dame who collaborated on the research – because it involves very high concentrations of an eternal chemical substance present in objects that are brought into contact with our skin for periods of time prolonged.”
The risks are unknown
According to the researchers, concentrations of Pfas above 1,000 parts per billion had never before been observed in a consumer good. However, it is good to remember that the risks that these substances could pose when they come into contact with the skin are currently unknown. The only existing legal limits concern the concentrations present in drinking water, and it is not certain that Pfas are actually able to overcome the barrier of the epidermis, and thus enter our organism in this way.
While waiting for science to delve deeper into the issue, those who want to avoid Pfas as a precaution have two choices: buy low-end smartwatches and fitness trackers, with silicone straps, or at least stay away from devices where their use is reported of fluoroelastomers, in case you decide to focus on higher-end products.