Old Navy, Lululemon: Traces of Toxic Chemicals Found in Yoga Pants

Some popular brands of yoga pants and gym leggings may contain measurable amounts of substances linked to cancer and other health risks, according to testing done by consumer health activist blog Mamavation.

The blog's author, eco-influencer and social media strategist Leah Segedie, said she sent 32 pairs of activewear from a variety of brands to an EPA-certified laboratory to check for a class of industrial chemicals known as PFAS.

PFAS, or per- and polyfluoroalkyl substances, are used in manufacturing and can linger in the environment and the human body over time, prompting the nickname "forever chemicals." They are linked to health risks like kidney and testicular cancers.

The results of Mamavation's specfic testing have yet to be replicated in a published study. However, this isn't the first time chemicals linked to cancer have shown up in clothing. Previously, PFAS have been found in waterproof and stain-resistant products, including outdoor gear and workout clothes.

Any amount in clothing should be avoided wherever possible, according to David Andrews, senior scientist for the Environmental Working Group, an advocacy and research organization specializing in toxins and corporate accountability

PFAS in clothing aren't regulated, and exposure through the skin is considered low-level, but the long-term health consequences are unclear.

PFAS include a broad range of compounds; researchers often test for them by screening for a specific substance called fluorine.

The lab test ordered by Mamavation specifically tested for fluorine in the crotch area of the clothes.

Products that were found to contain detectable levels of fluorine include a pair of pants from Lululemon, which contained 32 parts per million fluorine. Another Lululemon product did not test positive for fluorine.

The highest amount of fluorine, 284 parts per million, was found in a pair of leggings from LuLaRoe.

Fluorine was also detected in products from Athleta and Old Navy (17 parts per million each), both owned by Gap, Inc.

The brands mentioned did not respond to Insider's request for comment.

The full list can be found on the Mamavation website. The post was reviewed by environmental health researchers and partially funded by Environmental Health News.

It's unclear how risky PFAS in clothing might be for health, but even small amounts should be avoided when possible, Andrews told Insider.

"It's very difficult to completely avoid exposure to the compounds," he said. "Unnecessary exposure through clothing is adding to the burden of exposure through numerous sources."

Low-level exposures, including in the household and through clothing, may accumulate and cause potential health issues, according to the EPA.

Research has linked high levels of PFAS exposure to health issues like kidney and testicular cancers, liver damage, and developmental issues.

PFAS can show up in a variety of products, from cosmetics to bottled water. The riskiest exposure comes from ingesting the chemicals through contaminated food or water, or inhaling them in the air, according to research.

PFAS in manufactured clothing may not pose a direct risk to the wearer, Joe Schwarcz, director of the McGill University Office for Science and Society, wrote in an article for the McGill. But they can contribute to the chemicals leaching into the environment. Scientists have recommended phasing out PFAS to the reduce the risk of ongoing contamination, Bloomberg reported.

There are currently no federal regulations for PFAS, although states like New York have proposed regulatory legislation.