TOPLINE:

Perfluorohexanoic acid (PFHxA) is found in fluoroelastomer watch bands at concentrations of up to 16,662 ng/g, highlighting the need for further research on dermal absorption and exposure risks.

METHODOLOGY:

• Fluoroelastomers are a subclass of polymeric per- and polyfluoroalkyl substances (PFAS), which are used to help wearable device materials maintain their appearance and structure after contact with the skin, sweat, and personal care products (eg, sunscreen).
• Researchers investigated the presence of PFAS in 22 new and used US fitness and smart watch bands from a range of brands and price points, of which 13 were advertised as containing fluoroelastomers.
• Total fluorine concentrations were measured using particle-induced gamma-ray emission spectroscopy with cut pieces of the watch bands.
• Solvent extraction was performed, and targeted analysis for 20 PFAS compounds was conducted using liquid chromatography-tandem mass spectrometry.
• A subset of six watch bands, with the highest and lowest detectable PFAS concentrations (three each), was subjected to a direct total oxidative precursor assay to determine the presence of PFAS precursors.

TAKEAWAY:

• Watch bands advertised as containing fluoroelastomers had total fluorine concentrations ranging from 28.5% to 90.7%; only two of the nine bands not advertised to contain fluoroelastomers had concentrations of this PFAS, which ranged from 28.1% to 49.7%.
• Expensive watch bands showed high fluorine levels, with concentrations ranging from 49.7% to 90.7%, whereas inexpensive bands contained less than 1% fluorine on their surface.
• PFHxA was the most common PFAS, detected in 41% of the watch bands.
• PFXxA had a median concentration of 773 ng/g, much higher than the concentrations found in other consumer products, with one sample showing a concentration of 16,662 ng/g.
• Bands containing high PFHxA concentrations had total PFAS levels between 253 and 2016 ng/g, whereas those with low or no PFHxA concentrations had total PFAS levels between 3 and 24 ng/g.

IN PRACTICE:

“The thousands of ng/g of PFHxA available, paired with watch band users often wearing these items for more than 12 h per day, poses an opportunity for significant transfer to the dermis and subsequent human exposure,” the authors wrote.

“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,” said the study’s lead author in a press release.

SOURCE:

The study was led by Alyssa Wicks, University of Notre Dame, Notre Dame, Indiana, and published online in Environmental Science & Technology Letters.

LIMITATIONS: 

No limitations were reported in the study. 

DISCLOSURES:

The study received funding from the University of Notre Dame. The authors declared no competing financial interests.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.