Independent testing commissioned by the Center for Environmental Health found BPA in activewear from Nike, The North Face, New Balance and dozens of other brands, prompting Proposition 65 legal action in California. Here is what the testing showed, what the law requires, and what remains disputed.
The renewed attention on activewear chemicals traces back to a legal campaign rather than a fresh lawsuit filing. In 2022 and 2023, the Center for Environmental Health (CEH), a California nonprofit that uses laboratory testing and litigation to push toxic substances out of consumer products, commissioned independent testing of leggings, shorts, sports bras and athletic shirts from dozens of brands. The results prompted legal notices and civil complaints under California's Proposition 65, the state's right-to-know law on toxic exposure.
The brands named across CEH's notices and suits include Nike, The North Face, New Balance, Alo Yoga, Athleta, PINK (Victoria's Secret), Adidas, Patagonia, Champion, Fabletics, Sweaty Betty, Asics, FILA, Kohl's, Amazon Essentials, Outdoor Voices, Reebok, Mizuno, Beyond Yoga, Free People, Hoka, SoulCycle and Under Armour.
What the testing found
CEH's first wave of testing, reported in October 2022, found sports bras from Athleta, Nike, FILA, Asics, The North Face and PINK exposing wearers to BPA at up to 22 times California's warning threshold. A second round, published in May 2023, expanded the product list to leggings, shorts and athletic shirts and reported exposures up to 40 times that limit.
The threshold in question is 3 micrograms of BPA per day via skin exposure — the level above which Proposition 65 requires a cancer and reproductive harm warning on a product label. CEH's figures are calculated exposure estimates derived from lab measurements of fabric, not direct measurements of what enters a wearer's bloodstream.
BPA was detected only in polyester-spandex blends. The chemical is used in the manufacture of polycarbonate plastics and epoxy resins and is also applied in textile processing, leaving residue on fibers. A study published in Annals of Work Exposures and Health found roughly 25 percent of BPA on the skin surface can be absorbed within 24 hours — the basis for concern about garments worn for hours against the skin, particularly during exercise.
Why BPA draws regulatory scrutiny
BPA was first synthesized in the 1890s as a synthetic estrogen. It binds to estrogen receptors and can interfere with hormonal signaling. A review in Toxicology Letters described it as a compound with widespread human exposure and multiple effects, including reproductive and metabolic harm at low doses. Subsequent epidemiological reviews have reported associations between elevated BPA exposure and conditions including diminished ovarian reserve, endometriosis risk and polycystic ovary syndrome, though such studies establish correlation rather than causation.
CEH science director Jimena Diaz Leiva has said that even low levels of exposure during pregnancy have been associated with abnormal development of the mammary glands and ovaries that can raise later cancer risk. Kaya Allan Sugerman, who directs CEH's Illegal Toxic Threats program, framed the exposure pathway plainly: BPA can be absorbed through skin and reach the bloodstream after handling receipt paper for seconds, while sports bras and athletic shirts are worn for hours at a time and are designed to be sweated in.
Status and caveats
Two points matter for readers assessing the coverage now circulating. First, a Proposition 65 notice is an allegation, not a court finding; it triggers a 60-day window in which the state and alleged violators can act before a suit proceeds. CEH filed suit against several brands in California state court beginning in February 2023. The organization says it has pressed more than 100 companies to reformulate and remove bisphenols from products since 2021, and some have agreed to do so.
Second, there is no federal standard for BPA in textiles. Clothing makers are not required to disclose chemicals used in fabric manufacturing, and BPA does not appear on labels — which is precisely why Proposition 65, a California-specific statute, has become the primary enforcement channel in this area.
On the regulatory side, California's Office of Environmental Health Hazard Assessment is evaluating whether to add the broader class of p,p'-bisphenol to the Proposition 65 list, a move that would widen the scope of enforcement beyond BPA itself.
What it means
The legal exposure here is not a product recall story. It is a labeling and disclosure fight, with brands weighing the cost of reformulation against the cost of warnings and litigation. For consumers, the practical takeaway is narrower than some social media summaries suggest: the findings are product-specific, the brands involved dispute or have not conceded the allegations, and a warning threshold is not the same as a demonstrated injury threshold. What the case has established with more certainty is a gap — that shoppers currently have no reliable way to know what chemistry is in the synthetic fabric they wear to the gym.