New research from the University of Birmingham suggests that synthetic gym wear may release harmful chemical additives when you sweat, which can then be absorbed through the skin. The study focused on brominated flame retardants (BFRs), compounds used to prevent burning in fabrics and linked to thyroid disease, hormonal disruption, and neurological issues.
Researchers found that oily substances in sweat help leach these chemicals from plastic fibers. Dr Mohamed Abdallah, the study's principal investigator, explained that the oil in sweat encourages chemical additives to dissolve and diffuse, making them available for dermal absorption. While the study specifically examined flame retardants, Abdallah noted that other additives like bisphenols, phthalates, and PFAS may behave similarly.
Workout wear is often made from synthetic fabrics such as Spandex, nylon, and polyester, which are derived from petrochemicals and can contain harmful additives. Previous research has detected bisphenols at up to 40 times safe limits in popular sportswear brands. The Birmingham study raises concerns that repeated exposure through sweat could lead to bioaccumulation of these chemicals, potentially contributing to health issues.
Other recent studies highlight the prevalence of these chemicals. A study in Environmental Pollution found 25 flame retardants in breast milk samples from 50 US mothers, including compounds phased out a decade ago. Another study linked rising cancer rates in young Americans, particularly women, to exposure to pollutants and carcinogenic chemicals.
Alden Wicker, author of To Dye For: How Toxic Fashion is Making Us Sick, noted that sweat-wicking or water-repellent gym wear often contains PFAS, known as 'forever chemicals'. She also highlighted that polyester fabrics are typically dyed with disperse dyes, which can be skin irritants. The findings suggest that the more you sweat, the greater the potential chemical absorption.
