A pair of leggings is built to do quiet work on the mat: hold its shape in a deep lunge, stay opaque in a forward fold and move sweat away from the skin during a long flow. For years, some of that performance came from a family of fluorinated chemicals most practitioners never saw on a label, and a wave of state laws is now pushing them out of activewear on a schedule that tightens again in 2027.

The short version is that PFAS in activewear are being restricted state by state, with California's limit falling from 100 to 50 parts per million total organic fluorine on January 1, 2027, Vermont's following that July, and Washington's restriction on intentionally added PFAS in apparel starting the same year. The clearest signals for a shopper today are third-party certifications and a brand's written commitment, since the laws apply to what is sold from here forward rather than to what is already folded in your drawer.

What PFAS Were Doing in Workout Clothes

Per- and polyfluoroalkyl substances are prized by manufacturers because they repel water, oil and stains, and many break down very slowly. "One common characteristic of concern of PFAS is that many break down very slowly and can build up in people, animals, and the environment over time," the U.S. Environmental Protection Agency states.

Their presence in garments meant to handle sweat struck some chemists as odd. Richard Blackburn, a professor of sustainable materials at the University of Leeds, called it "counterintuitive for PFAS, compounds that repel water, to be added to sweat-wicking athletic clothes," in an interview with Environmental Health News.

The EPA lists health effects that peer-reviewed studies have associated with exposure to certain levels of some PFAS, including decreased fertility, developmental delays in children, increased risk of some cancers such as kidney and testicular cancer, reduced vaccine response and higher cholesterol. The agency frames those associations around exposure to certain levels of PFAS, not around any single product category.

What the Testing Found

Testing commissioned by the wellness site Mamavation at an EPA-certified lab found fluorine between 10 and 284 parts per million in eight of 32 pairs of leggings and pants, using fluorine above 10 parts per million as an indication of PFAS, as Environmental Health News reported. A second round found detectable fluorine in 15 of 23 popular sports bras, at levels from 10 to 58 parts per million, according to a follow-up report.

Total fluorine is a screening measure rather than an identification of specific chemicals, and the researchers who use it say so. "It's a really great screening tool because it tells you where you should be targeting your resources to identify the products that need to be investigated further," Carla Ng, a University of Pittsburgh engineer who studies PFAS, told Environmental Health News.

Broader product testing pointed in the same direction for performance finishes. In a 2022 study of 60 products bought from 10 major retailers, Toxic-Free Future found PFAS in 72 percent of the 47 products marketed as stain- or water-resistant, among them rain jackets and hiking pants, according to the group's release.

Can PFAS move from fabric into skin?

A 2024 University of Birmingham study using three-dimensional human skin models found that 15 of 17 PFAS tested showed substantial absorption of at least 5 percent of the applied dose, with 13.5 percent of PFOA reaching the equivalent of the bloodstream and a further 38 percent retained in the skin, the university reported. "The ability of these chemicals to be absorbed through skin has previously been dismissed because the molecules are ionised," said lead author Oddný Ragnarsdóttir.

That study applied chemicals directly to lab-grown skin rather than testing garments or sweat, and the open question was framed precisely by Pete Myers, chief scientist at Environmental Health Sciences, in the original leggings report. "While we know that PFAS can be absorbed through the skin we don't have much information about how much would be transferred from activewear products," he said. "It's unlikely to be zero."

The State Laws and Their Dates

California moved first with AB 1817, signed in September 2022, which since January 1, 2025 has barred textile articles with intentionally added PFAS or total organic fluorine above 100 parts per million, a threshold that falls to 50 parts per million on January 1, 2027, according to analyses by Venable and Kelley Drye. Outdoor apparel for severe wet conditions is exempt until 2028 but must carry a "Made with PFAS chemicals" disclosure in the meantime.

New York's apparel law, as amended in 2023, has prohibited the sale of new apparel containing intentionally added PFAS since January 1, 2025, with severe-wet-conditions outerwear following on January 1, 2028, according to the state Department of Environmental Conservation.

Maine's ban on textile articles with intentionally added PFAS took effect January 1, 2026, with a broader prohibition across most products slated for 2032, according to Maine's Department of Environmental Protection. Vermont's textile rule began in 2026 at 100 parts per million total organic fluorine and drops to 50 after July 1, 2027, and Connecticut's apparel ban took effect July 1, 2026, according to a January summary by Morgan Lewis.

Washington's Department of Ecology adopted a rule in November 2025 restricting intentionally added PFAS in apparel beginning January 1, 2027, with a 50 parts per million total fluorine threshold, as Exponent summarized it. Colorado's law bans textile articles with intentionally added PFAS from January 1, 2028, according to the state legislature's bill summary.

What Brands Say

Patagonia states that from the Spring 2025 season, all of its new products are made without intentionally added PFAS, on its company page. Gap Inc., which owns Athleta, committed to eliminating PFAS-based water-repellent, stain-repellent and other finishes from its supply chain by January 2023, according to its environmental policies, which do not report brand-level results.

A lululemon spokesperson told ESG Dive in April that the company does not use PFAS in its products and phased them out in 2023, a statement made while the Texas attorney general's office was investigating the company's activewear claims. The 2022 leggings screen had flagged its Align style.

How to Shop Now

Certifications offer the most practical shortcut. OEKO-TEX Standard 100 has carried a general ban on PFAS in certified textiles since its 2023 rule update, according to OEKO-TEX, and bluesign says it fully restricted PFAS in approved materials, outside essential uses, from January 2025, on its PFAS page.

Read marketing language closely, because a "PFC-free" claim can refer to only a subset of the chemical family, and "PFOA-free" means only that one compound is absent. Treat stain-proof or water-repellent claims on studio clothes as a prompt to check the brand's chemical policy, since a yoga practice rarely calls for either feature.

Keep the pieces you already own if they fit and serve you, since replacing a drawer of clothes carries its own environmental cost, and the testing so far describes signals rather than measured doses from wear. Our guide to closed-loop fabrics in yoga gear covers the materials side of that decision, and the 2026 sustainable mat guide applies the same scrutiny to what sits under your feet.

When the next round of leggings arrives on shelves in January, California's 50 parts per million line will govern what can be sold there, Washington's restriction will begin, and Vermont's lower threshold will follow six months later.