Are Leggings Toxic? Top brands Athleta, Alo Yoga, Sweaty Betty & Lulu Lemon tested for "Forever Chemicals".

Could your workout gear be putting your health at risk? That depends on what you’re wearing. Testing conducted by consumer health advocacy group Mamavation found that yoga pants and gym leggings from Lululemon and other major sportswear brands contain PFAS, or “forever chemicals.” In this article, we explore why these hazardous chemicals have persisted in activewear, the extent of their health risks, and safer, non-toxic alternatives.

A Brief History of Polyester in Activewear

You might be wondering: if polyester poses health risks, why is it so widely used? Polyester has only been part of the clothing industry for less than 50 years. Previously, people relied on natural fabrics like silk, linen, wool, and cotton, often owning just a few garments due to the high cost of quality materials. With technological advancements in the 1950s, synthetic polymers became possible, and by the 1970s and 80s, they were widely adopted in clothing and sportswear.

Today, most yoga and workout apparel from brands such as Lululemon and Alo is made from polyester or similar synthetics. These fabrics are prized for their durability and “sweat-wicking” qualities, but the primary driver is cost-effective manufacturing, which maximizes profits.

Because synthetic clothing has only been mainstream for a few decades, the long-term health effects weren’t studied until relatively recently. Research over the past ten years has revealed alarming findings about the impact of chemicals in synthetic fabrics on the human body.

Erik Olson, Senior Strategic Director for the US Natural Resources Defense Council, describes the situation: there is a “tidal wave of research that’s been coming out fast and furious.” He adds, “we’re getting past the phase of complete denial from the industry – they can no longer claim that there’s no risk.”

As global concern grows, synthetic sportswear is emerging as a potential public health issue. While exercise is more popular than ever, toxic activewear could become this century’s equivalent of the smoking-related health crisis.

Health Impacts of Toxins in Polyester

Synthetic fabrics are created from chemical compounds. Polyester, for example, contains dyes, solvents, phthalates (plasticizers), and PFCs — now more commonly referred to as PFAS (per- and polyfluoroalkyl substances).

PFAS are virtually indestructible. While they’re useful in products like car wax, their effects on human health are concerning. These chemicals can disrupt the skin’s natural microbiome, causing clogged pores, irritation, dermatitis, and allergic reactions.

But the risks extend beyond the skin. PFAS can enter the bloodstream, posing more serious health threats. Exposure to PFAS in polyester has been linked to:

• Birth defects

• Miscarriage and infertility

• Thyroid irregularities

• Hormone disruption

• Weight gain

• Elevated cholesterol

• Liver inflammation

• Compromised immune function

• Cancer

PFAS are harmful even at extremely low concentrations, such as parts per quadrillion. The Mamavation study, conducted at an EPA-certified lab, detected 32 parts per million (ppm) of organic fluoride (a PFAS indicator) in Lululemon Align High-Rise Pants.

Although the full health implications are still being investigated, research by the National Institute for Occupational Safety and Health shows that skin exposure to PFAS can be as dangerous as ingesting them via food or water.

Because clothing contacts the body for extended periods, exposure isn’t just a one-time event. Alexandra McNair Quinn, chemical sustainability consultant and founder of Fashion FWD, notes: “It’s not just that people are exposed to one on a regular day. It’s the accumulation of all of these exposures in a regular day that can be harmful.”

Another chemical commonly used in polyester is formaldehyde, which prevents shrinking. Unfortunately, formaldehyde is classified as a class-three carcinogen and can cause respiratory issues.

The Environment of Synthetic Fabrics

The risks of synthetic clothing extend beyond their chemical composition. Polyester is derived from petroleum, has low water permeability, and does not absorb sweat effectively. It also prevents the body from breathing properly, disrupting natural heat regulation and airflow. During exercise, body heat, sweat, and friction can accelerate the absorption of toxins into the skin.

Organizations like Greenpeace are pressuring sports brands to reduce chemicals in activewear. However, in many countries, including the U.S., regulation is limited, and the multi-billion-dollar industry has been slow to address this issue.

Non-Toxic Alternatives

Consumers want clothing that is both functional and safe. Sujatha Bergen, co-author of the NRDC report Going Out of Fashion: U.S. Apparel Manufacturers Must Eliminate PFAS “Forever Chemicals” from Their Supply Chains, emphasizes: “We lived just fine without these chemicals before, and brands could phase them out quickly if they chose to.”

Can high-performance sports apparel be made without these chemicals? Traditional natural fabrics like cotton often struggle to achieve “sweat-wicking” performance, tending to hold moisture and become heavy or uncomfortable.

Dojo Sportswear has developed an innovative solution. Their patented textile combines natural minerals with premium cotton, creating a fabric that delivers all the benefits of synthetics without toxic chemicals.

Dojo Yoga Leggings offer sweat-wicking, breathability, and durability, while remaining non-toxic, odor-repelling, anti-bacterial, and hypoallergenic. Learn more about this revolutionary mineral-based fabric here.