Does Polyester Cause Cancer? What the Research Actually Says

The short answer: polyester itself has not been shown to cause cancer in people who wear it. No human study has established that a polyester shirt, pair of leggings, or underwear raises cancer risk. The documented questions concern substances that may be used to make or finish synthetic fabrics, including antimony catalysts, disperse dyes, and PFAS finishes. Researchers are also studying microplastic fibers. A hazard is not the same as the risk from wearing a garment. The evidence supports informed choices, not panic. For health questions beyond cancer, see this broader look at polyester and health.

Where the cancer worry comes from

Antimony trioxide is used to make polyester

Most clothing polyester is polyethylene terephthalate, or PET. Antimony compounds are commonly used as catalysts during PET production, so finished polyester can contain antimony residue. A 2021 peer-reviewed study by Biver, Turner, and Filella tested polyester textiles in artificial sweat. Under its default laboratory conditions, about 0.05 to 2 percent of the measured antimony moved into the solution. It did not measure absorption through human skin, an internal dose, or cancer. The first extraction released the most antimony, so the authors suggested washing garments before use. Read the study in Regulatory Toxicology and Pharmacology.

Older articles may call antimony trioxide a Group 2B possible carcinogen, its 1989 classification. IARC now classifies trivalent antimony, which includes antimony trioxide, as probably carcinogenic to humans in Group 2A. IARC reported limited human evidence for lung cancer, sufficient evidence in animals, and strong mechanistic evidence. Its categories identify hazards, not the cancer risk at a given dose or in a given scenario. The agency discusses occupational exposure in mining, smelting, and antimony production. It does not identify wearing polyester clothing as a cause of cancer. See IARC's explanation of the classification and its limits.

Disperse dyes can cause skin allergy

Disperse dyes are used to color synthetic fibers such as polyester. Their best documented consumer health concern is allergic contact dermatitis, not cancer. A peer-reviewed review found that several disperse dyes remain important allergens in textile dermatitis. A later clinical study noted that skin exposed to close fabric contact, friction, and perspiration is more vulnerable to textile dye allergy. That can look like itching, redness, or eczema where clothing fits tightly. These findings support taking a recurring rash seriously, but they do not show that dyed polyester clothing causes cancer. Read the disperse dye review and the 2023 patch-testing study.

Some performance finishes contain PFAS

PFAS are not an essential part of polyester fiber. They may be added to natural or synthetic textiles to resist water, oil, soil, or stains. An EPA report documents those uses. A peer-reviewed study of 72 children's stain-resistant textile products found PFAS in tested school uniforms. That does not mean every uniform, polyester garment, or piece of activewear contains PFAS. It shows why the finish and test results matter more than the fiber label alone. Read the EPA textile report and the school uniform study.

The EPA says exposure to certain levels of some PFAS may increase the risk of prostate, kidney, and testicular cancers. It also says effects vary by compound, dose, timing, and exposure route, and that research is ongoing. The broader PFAS evidence does not establish that wearing a PFAS-treated garment causes cancer. This PFAS explainer covers how the finishes are used in clothing and what labels can tell you. See the EPA's current health summary.

Polyester sheds microplastics

Polyester textiles can release microplastic fibers and smaller particles during washing and abrasion. A 2021 peer-reviewed study confirmed microplastic and nanoplastic release from tested polyester fabrics under laboratory conditions. This is clear evidence of shedding, but it is not evidence that wearing polyester causes cancer. Read the textile shedding study.

The health research is still developing. In 2024, NIH said scientists knew very little about the short-term or long-term effects of microplastics on human health. A 2024 rapid systematic review concluded that microplastics are suspected to harm digestive, reproductive, and respiratory health, with a suggested link to colon and lung cancer. Yet that review included only three human observational studies and 28 animal studies. It did not study cancer rates among people who wear polyester. This is a reason for better research and reasonable exposure reduction, not a basis for claiming that polyester clothing causes cancer. See the NIH research summary and the systematic review.

What the evidence does not show

There is no human epidemiological evidence showing that ordinary wear of polyester clothing increases cancer risk. The IARC antimony classification does not classify polyester fabric as carcinogenic. The artificial sweat study measured release from fabric, not movement through skin or a health outcome. The microplastics review covers many polymers and exposure routes. It does not isolate wearing polyester as a cause of cancer.

Dose and route matter. Breathing a substance at work for years, swallowing it in contaminated water, and having trace residue against intact skin are different exposure scenarios. IARC explicitly warns that agents in the same hazard group can carry very different risks depending on the type and extent of exposure. It would be equally inaccurate to say that all polyester is dangerous or that every possible concern has been ruled out.

Who might reasonably care anyway

• People with eczema, sensitive skin, or a known textile dye allergy may prefer fabrics and dyes that do not trigger symptoms. A recurring rash under tight clothing is a sound reason to stop wearing that item and talk with a clinician. Clinical patch-testing research supports the link between textile dyes and allergic contact dermatitis.

• People who sweat heavily in close-fitting clothing may choose a cautious approach. Perspiration and friction are relevant to textile dermatitis, and artificial sweat testing found that temperature and pH affected antimony release in the laboratory.

• People choosing daily-wear items such as leggings, underwear, and sleepwear may decide that long skin contact makes fiber choice and finish disclosure worth more attention, even while the cancer evidence remains unproven.

How to reduce exposure without panic

• Choose mostly natural fibers for sweat-zone garments if that fits your budget and comfort needs. This reduces direct contact with polyester, but natural fiber does not mean chemical-free. Dyes and finishes still matter.

• Wash new clothing before wearing it. The antimony release study found the greatest release in the first extraction. Washing may remove some readily released residue, though it cannot verify that every finish is gone.

• Avoid stain-resistant, oil-resistant, or water-repellent finishes when you do not need them. If you do need that function, look for a clear PFAS-free statement backed by testing.

• Look for third-party evidence. A useful lab report names the sample, method, compounds tested, detection limits, result, and laboratory. Broad claims such as clean or non-toxic tell you much less.

• Make gradual changes. Current evidence does not support throwing away a working wardrobe. Replacing the most frequently worn, tightest, or most sweat-exposed items first is a practical precaution.

Where PuraKai fits

At PuraKai, we make activewear with GOTS-certified organic cotton. Our PureFlex activewear fabric is 92% organic cotton with 8% spandex, and our garments are knit, cut, sewn, and dyed in Los Angeles using cotton grown in Texas, Turkey, and India. Our organic cotton leggings are part of our lab-tested PFAS-free activewear, with fabric independently lab-tested PFAS-free by Applied Technical Services, an independent lab accredited to ISO/IEC 17025 by A2LA, as shown in the lab report.

FAQ

Is polyester carcinogenic?

Polyester fabric has not been shown to cause cancer in humans who wear it. IARC's Group 2A classification applies to trivalent antimony, not to polyester clothing. The classification identifies a potential cancer hazard and does not calculate the risk from skin contact with a garment.

Does wearing polyester underwear or leggings cause cancer?

No study has shown that polyester underwear or leggings cause cancer in people. Someone with skin irritation or a preference for precaution may still choose cotton-rich options for garments worn tightly and for long periods.

Should I get rid of all my polyester clothing?

No. The evidence does not support a purge. Wash new items, avoid unneeded stain or water-repellent finishes, check testing when available, and replace high-contact garments over time if you want to reduce synthetic fiber use.