American Chemical Society Dec 19 2024 Smartwatches and fitness trackers have become ubiquitous forms of wearable tech, accompanying many people throughout their days (and nights). But they may expose the skin to so-called forever chemicals in the process. More expensive wristbands made from fluorinated synthetic rubber revealed particularly high amounts of one forever chemical, perfluorohexanoic acid (PFHxA), according to a study published in ACS' Environmental Science & Technology Letters .