Spandex itself is not inherently made with PFAS, but many spandex-blend garments, particularly activewear like leggings and yoga pants, do contain detectable levels of these chemicals. PFAS are typically added during manufacturing as water-resistant, stain-resistant, or moisture-wicking finishes rather than being part of the elastic fiber itself. Testing by the consumer advocacy group Mamavation found that one in four pairs of popular leggings and yoga pants had detectable fluorine levels, a key marker for PFAS contamination.
What Testing Has Found in Activewear
Out of 32 pairs of leggings and yoga pants tested by an EPA-certified lab, eight showed fluorine levels ranging from 10 parts per million (ppm) up to 284 ppm. The testing was conducted on the crotch area of the pants, where skin contact is most intimate and prolonged. Any garment with more than 10 ppm of fluorine was flagged as containing likely PFAS.
The distinction matters: spandex (also called elastane or Lycra) is a stretchy polymer. On its own, it doesn’t require PFAS to function. But manufacturers often apply chemical finishes to the completed fabric blend to add properties like water repellency, odor resistance, or durability. These finishes are where PFAS typically enter the picture. You can’t tell by looking at a garment or reading its fiber content label whether those finishes were applied.
How PFAS Transfer From Clothing to Your Body
Wearing PFAS-treated clothing isn’t the same as ingesting contaminated water, but the chemicals can still reach your body through your skin. A study published in Science of the Total Environment found that sweat dramatically increases this transfer. When skin is dry, very little moves from fabric to body. But sweating amplified PFAS absorption by up to 3,252 times compared to dry contact. That finding is particularly relevant for activewear, which is designed to be worn during exercise, exactly when you’re sweating the most.
This doesn’t mean a single workout in treated leggings poses an acute health risk. But PFAS are called “forever chemicals” because they don’t break down in the body or the environment. They accumulate over time, and repeated exposure from clothing worn against sweaty skin adds to your overall PFAS burden from drinking water, food packaging, and other sources.
PFAS Also Leave Through Your Washing Machine
The chemicals don’t just stay on your skin. Every time you wash spandex-blend activewear, the garments shed synthetic microfibers into the water. A single laundry load can release upwards of 700,000 microfibers, and research analyzing those fibers found PFAS compounds on 87.3% of samples tested. The fibers, mostly polyester, nylon, and acrylic, act as tiny rafts carrying PFAS into wastewater treatment systems that aren’t equipped to filter them out. This is one of the ways PFAS from clothing cycle back into water supplies.
California’s Ban on PFAS in Clothing
As of January 1, 2025, California prohibits the manufacture, distribution, or sale of new textile articles containing regulated PFAS in the state. The law, Assembly Bill 1817, covers a broad range of clothing: undergarments, leggings, athletic wear, swimwear, dancewear, school uniforms, and outdoor apparel. It also extends to household textiles like bedding, towels, and curtains. Manufacturers selling in California must also use the least toxic alternative when reformulating their products.
There are exceptions. Personal protective equipment, military clothing, vehicle components, marine products like boat covers, and industrial filtration media are all exempt. But for everyday activewear, the law applies broadly. If you’re buying new leggings or yoga pants sold in California, they should be PFAS-free under this regulation.
How to Find PFAS-Free Options
The most reliable indicator is third-party certification. OEKO-TEX, one of the most widely recognized textile safety standards, has implemented a general ban on intentional PFAS use across all its certifications. Starting January 2026, certified products must meet a limit of 25 parts per billion for each regulated PFAS substance, with total fluorine limits dropping from 100 ppm to 50 ppm for products sold in California. If a garment carries the OEKO-TEX Standard 100 label, it has been tested against these thresholds.
Several brands have built their lines around avoiding PFAS entirely. MATE the Label uses organic cotton in various weaves, including stretch fabrics, along with TENCEL lyocell and linen. ADAY works with OEKO-TEX certified modal and wool blends. Everlane has introduced Roica V550 yarn, a stretch fiber manufactured without harmful chemicals, into their products as a spandex alternative. These brands offer the stretch and performance feel of traditional activewear without relying on PFAS-treated finishes.
When shopping without brand-specific guidance, look for garments labeled OEKO-TEX Standard 100 certified, or check whether the brand publishes chemical transparency reports. Terms like “water-resistant” or “stain-resistant” on activewear labels can signal PFAS treatment, though not always. The absence of those marketing claims is a reasonable, if imperfect, starting point when certification labels aren’t available.