The first thing that happened when Mary, an Alaska Airlines attendant, received a new, high-performance, synthetic uniform in the spring of 2011 was a hacking cough. Then a rash bloomed on her chest. Next came migraines, brain fog, a racing heart, and blurry vision.

Mary (whose name I’ve withheld to protect her job) was one of hundreds of Alaska Airlines attendants reporting that year that the uniforms were causing blistering rashes, swollen eyelids crusted with pus, hives, and in the most serious case, breathing problems and allergic reactions so severe that one attendant, John, had to be taken off the plane and to the ER multiple times.

Tests commissioned by Alaska Airlines and the flight attendants’ union turned up tributyl phosphate, lead, arsenic, cobalt, antimony, restricted disperse dyes known to cause allergic reactions, toluene, hexavalent chromium, and dimethyl fumarate, an antifungal that had recently been banned in the European Union. But the uniform maker, Twin Hill, avoided culpability in court by saying none of these many mixed chemicals, on their own, were present at high enough levels to cause all of the different reactions. Alaska Airlines announced in 2013 it would procure new uniforms, without admitting the uniforms had caused health issues. A lawsuit from attendants against Twin Hill was thrown out in 2016 for lack of evidence.

But a 2018 Harvard study found that after the introduction of the uniforms, the number of attendants with multiple chemical sensitivity, sore throats, cough, shortness of breath, itchy skin, rashes and hives, itchy eyes, loss of voice, and blurred vision had all more or less doubled. “This study found a relationship between health complaints and the introduction of new uniforms,” the study’s authors concluded.

In 2021, John, who had been in perfect health before the introduction of the uniforms, died at age 66 after years of seeking and failing to find treatment for his symptoms. The official cause of his death was cardiopulmonary arrest, secondary asthma. Mary, who has continued with some difficulty to work for Alaska Airlines, last year was diagnosed with three autoimmune diseases: mixed connective tissue disease, lupus, and Sjögren’s. Mary and John’s surviving partner say the uniforms were the culprit.

This story of sick attendants has played out again and again, as American Airlines, Delta, and Southwest all introduced new uniforms, which were brightly colored polyester instead of the old standby, wool, and were layered with anti-wrinkle, stain-resistant, and flame-retardant textile technology.

Mary and John are far from alone. The impact of exposure to harmful chemicals on textile workers, many of whom work in developing countries, has been well documented and includes breathing problems, rashes, and even death, but I was less aware that so many in the US were reporting ill effects simply from wearing garments. Rather, as I discovered while researching my book To Dye For: How Toxic Fashion is Making us Sick – and How We Can Fight Back, they are part of a diverse and disparate cohort of people who believe they have suffered from the health effects of toxic fashion.

“Flight attendants are the canary in the coalmine because of the length and consistency of their exposure,” said Dr Irina Mordukhovich, one of the Harvard study’s authors. “That doesn’t mean that other people in the population are not still being affected in some way. Let’s say someone has Clothing with the same components – they may not even notice; they just don’t wear it so much.”

Karly Hiser is a pediatric nurse practitioner in Grand Rapids, Michigan. Her oldest son was a toddler when his eczema worsened, she said. She switched her family to fragrance-​free soaps and non-toxic cleaning products, and smeared him with lotion, Vaseline, and prescription steroid cream after long baths. “Everything we tried did not help,” she said. Open wounds developed on his hands and behind his knees, and they got infected.

Like any parent on a budget, Hiser had been buying cheap clothing from mass-​market brands, including polyester athletic clothes, but he was refusing to put his clothes on. “He’s a really sweet, nice, low-​key kid. And every morning getting dressed was a nightmare, just screaming tantrums,” she said. The thing that finally made her kid’s eczema manageable, she said, was pulling out her grandmother’s sewing machine, buying non-toxic fabric from an online store, and sewing all his clothes herself.

Despite her job as a nurse practitioner, it took Hiser over a year to figure out what she now firmly believes: that the clothes were the problem. “You know, like the nutrition labeling for food, I would prefer if there was better labeling for clothing,” she said. “Not all chemicals are bad or harmful, but I would like to at least be aware of what’s in children’s clothing.”

Jaclyn is a former fashion production manager in New York City. She told me about her experience opening boxes of samples from Asia and South America every day and being hit in the face with the pungent smell of synthetic chemicals. After years of touching this freshly made clothing, she developed rashes on her hands and arms. When her dermatologist tested her for allergies, she found out she was allergic to several chemicals typically used in fashion production, including a blue disperse dye used to dye polyester. Unfortunately, there was nothing she could do to protect herself – all those allergens are perfectly legal to put on and in clothing. Even if she quit her job, she has to wear clothing to live. Her health spiraled after that, a result, she believes, of the stress of her job combined with touching and breathing in fashion chemicals day in and day out.

Chemicals in clothing are a complex, opaque and an under-researched area. “There’s not necessarily a lot of evidence that goes into deciding what is a safe limit of a chemical,” Mordukhovich said. “Even if each chemical is below thresholds that would be considered a direct safety issue, what we don’t know is if you have hundreds of chemicals interacting together, what effects does that have?”

Even if each chemical is below safety thresholds, if you have hundreds of chemicals interacting, what effects does that have?

For her PhD at Duke’s department of integrated toxicology and environmental health, Dr Kirsten Overdahl spent years distilling and cataloging disperse dyes in an effort to prove, in paper submitted for peer review, that they are skin sensitizers. Most are not even labeled or cataloged in the literature, much less tested for safety. “I see every day, just in our raw data that the instruments produce, that there are often thousands of chemicals in a sample that can’t be matched to a known chemical. That’s absolutely terrifying,” she said. “This doesn’t mean that every chemical is bad. Maybe it’s harmless. But if we can’t match a name to a chemical structure, it means that the data is not out there. So you can’t say it’s not safe, but you also can’t say it is safe.”

Recently, researchers and advocates have ramped up the practice of buying and testing regular garments and the results are illuminating. The Center for Environmental Health in California has found high levels of the hormone-disrupting chemical BPA in polyester-spandex socks and sports bras by dozens of large brands, including Nike, Athleta, Hanes, Champion, New Balance, and Fruit of the Loom, at up to 19 times California’s safety limit.

When the Canadian Broadcasting Corporation had 38 pieces of children’s clothing tested from the ultra-​fast-​fashion brands Zaful, AliExpress, and Shein, it found that one in five had elevated levels of toxic chemicals such as lead, PFAS, and phthalates. This year, the period panty brand Thinx settled a lawsuit stemming from a test by a Notre Dame professor showing high levels of fluorine, indicating the presence of PFAS, a highly toxic class of “forever chemicals” that provide water and stain repellency.

Some of the chemicals scientists have found in garments – such as tributyl phosphate, dimethyl fumarate, and disperse dyes – can be acutely toxic or hazardous, causing skin reactions or asthma. Others have been proven, outside of their use on clothing, to have links to cancer, reproductive toxicity, allergies, and skin sensitization.

A 2022 study by Professor Miriam Diamond at the University of Toronto and Professor Graham Peaslee at Notre Dame estimated, meanwhile, that on average, children wearing stain-​resistant school uniforms would be exposed to 1.03 parts per billion of PFAS per kilogram of their body weight per day through their skin. PFAS have been connected to several cancers, fetal abnormalities, reproductive disorders, obesity, and reduced immune system function. When it accumulates in the blood, PFAS are considered toxic at the parts-​per-​billion level. More research is needed on how readily PFAS shed from clothing can be absorbed into the skin and bloodstream, but the results are alarming enough to spur firefighters to revolt against their PFAS-laden turnout gear.

Some chemicals found in clothing, such as BPA, PFAS, and phthalates, have been found in time-bound experiments and longitudinal studies to mimic hormones and interfere with our endocrine system, causing a little-understood cascade of health effects ranging from extreme weight fluctuations and fatigue to infertility and chronic disease.

Once exposure stops, some chemicals, such as BPA, can be metabolized and peed out by the body, eventually breaking down and going away. Others, such as heavy metals, accumulate in the body and in the environment, lasting for decades or, in the case of PFAS, forever.

It’s a physical reality that the chemicals migrate to your skin from your clothing

When tested in contexts other than fashion, many of these substances, such as pesticides and solvents, have been found to damage the body over years of chronic, yet infinitesimally small exposure. Their presence in fashion worries some experts. As Diamond at the University of Toronto told me: “We know that chemicals are continually lost from any material over time. It’s a physical reality that the chemicals migrate to your skin from your clothing, with and without sweat.”

“We see the trends, but we cannot nail the trends to this and that chemical,” Dr Åke Bergman, a Swedish environmental toxicologist who specializes in endocrine disruptors, told me in 2021 about the rise of reproductive disorders and infertility. He was part of a taskforce convened in 2020 to advise Sweden on taxing toxic chemicals used in fashion. “There is an enormous use of a large number of chemicals. We strongly feel that there is a link between the exposures to these chemicals and the effects that are observed.”

For all the evidence, however – the toxic test results that are piling up, the researchers and advocates in the North America and Europe ringing the alarm, the reports of skin burns from shoes, tights, and bras on the Consumer Product Safety Commission’s website – this is an extremely difficult subject to make conclusive statements about, and an unpopular area of scientific research. There are no studies linking the experiences of fashion and airline employees with the experiences of the general population, nor studies examining the effects of chronic, everyday exposure through wearing textiles with these hazardous contaminants and finishes next to our skin. Meanwhile, fashion’s very complexity lends itself to obfuscation and confusion.

In the US, there are no federal standards for what can be put on clothing and sold to adults. The EU has banned more than 30 substances for use in fashion, and it will reject some shipments at the border, but its testing program is small and easily skirted.

Beyond fashion, it’s clear that many Americans are concerned that the government is falling down on its job of protecting us from harmful substances. Organic food promising to be free of pesticide residues is the fastest growing sector in the food market, with sales hitting $57.5bn in 2021. Beauty has followed close behind, with millions of women overhauling their entire bathroom cabinets in the past decade, throwing out legacy brands with toxic ingredients like phthalates and parabens. Influencers, bloggers, and beauty brands have stoked this fear and distrust to garner engagement and sell products – while often going too far in demonizing perfectly safe substances.

Yet fashion, a $2.5-tn global industry, has somehow completely evaded the same scrutiny.

One reason is that neither consumers or professionals know which, or even how many, chemical substances are used to manufacture, process, weave, dye, finish, and assemble clothing and accessories.

“It’s becoming more difficult to avoid these chemicals,” Dr Elizabeth Seymour, at the Environmental Health Center in Dallas, says of additives like solvents and heavy metals. “There are multiple chemicals that are put in everything. And your clothing is included in that.” But while beauty, cleaning products, and packaged foods come with an ingredient list, fashion does not, even though testing reveals it has some of the most complicated and multilayered chemical profiles of any product, running up to 50 chemicals or more.

Having researched this for two years, I am more careful now with my own clothing. I avoid cheap, knock-off, or ultra-fast fashion brands. I shop with companies I trust, who care about their reputation and have a chemical management program or labels such as bluesign, Oeko-Tex, or GOTS. I choose natural fibers whenever possible, and avoid fancy promises like stain repellency, anti-odor finishes, easy-care and anti-wrinkle fabrics. I wash any new clothing before I wear it, with unscented, non-toxic laundry detergent. And I trust my nose – if something stinks, I send it back.

But what I really want to see is action from our governments. A few states have labeling requirements or forthcoming bans on PFAS in clothing, but the federal government does not regulate what chemicals can be put on clothing and sold to adult consumers. We need a total overhaul of how we manage chemicals in consumer products in this country.

I would like to see the federal government catch up to the good work being done by the European Union – and go beyond it. It should implement taxes and tariffs on untested chemicals to fund desperately needed research, require chemical companies to register all chemicals in use and share any associated research, ban certain classes of chemicals for use in fashion, and expand the Consumer Product Safety Commission’s ability to test and recall toxic fashion.

These may seem like some big asks. So maybe we could start simple. Let’s require fashion to come with an ingredient list – a truly complete ingredient list. Because if consumers really knew what was in their clothes, well, they might not want to wear them.