The study, published in the journal Environmental and Science Technology, detected the chemicals in 65 percent of school uniforms, raincoats, snowsuits, snowshoes, gloves, bibs, hats and stroller covers, and at levels the authors described as “high.” “It’s one of those things where you hang your head and go, ‘What are they thinking?’ said co-author and University of Notre Dame researcher Graham Peaslee. “Everyone thinks stain-resistant clothing is great progress, but if little Johnny or Jane is covered in PFAS, is it great progress?” PFAS, or per and polyfluoroalkyl substances, are a class of about 12,000 compounds used to make consumer products resistant to water, stains and heat. They are called “forever chemicals” because they do not break down naturally and accumulate in the environment and the human body. Researchers have linked PFAS to cancer, birth defects, kidney disease, reduced immunity, reproductive problems and other serious health problems. The study of fabrics purchased in the US and Canada builds on previous studies that found the toxic compounds in children’s outdoor clothing, but is the first to look at their use in school uniforms and other children’s indoor clothing. Peaslee said the only fabric he had found higher levels of PFAS in than school uniforms was turnout gear used to protect firefighters. The new study found PFAS in all “resistant” school uniforms tested from nine “popular brands.” The chemicals were found in uniforms made of 100% cotton, cotton spandex and cotton polyester. It is estimated that about a quarter of all school-aged children in the US wear uniforms, and they are usually required in low-income, Catholic and other private elementary schools. The most commonly detected PFAS compound was 6:2 FTOH, which is also used in floor wax, food packaging and water sealants. The Guardian previously revealed that PFAS producers such as DuPont and Daikin had hidden the dangers of FTOH 6:2 by failing to tell regulators that animals exposed to the compound at very low levels in laboratory tests suffered kidney failure, liver damage, problems mammary glands, tooth spots. and other issues. PFAS can be absorbed through the skin, inhaled when it comes off clothing, or ingested through hand-to-mouth contact. Children are particularly vulnerable because they have a smaller body mass and their bodies and organs are developing. The study’s authors say it’s best to avoid clothing with labels like “stain-resistant,” “weather-resistant,” or “waterproof” and urge schools to order PFAS-free products. “I don’t know any parent who values stain repellency over their child’s health,” said Miriam Diamond, co-author and professor at the University of Toronto. The testing comes as New York and California prepare to ban the use of PFAS in textiles.