Does Oeko-Tex Certification Mean a Product Is Safe?

Image credit: Oeko-Tex. This is an excerpt from To Dye For: How Toxic Fashion Is Making Us Sick –– and How We Can Fight Back. 

It was the spring of 2021, and my bookkeeper was confused. She emailed me, asking gently whether someone had hacked the PayPal account for EcoCult and gone on a shopping spree. There were a dozen purchases at brands she knew I would never shop at. “Don’t worry,” I responded. “It was me. I’m going to have them tested for toxins.” With the supposed gold standard for non-toxic clothing certification: Oeko-Tex.

Not long after, a dear friend stopped by. We were catching up on the couch with glasses of white wine, the pile of bags and boxes within arm’s reach on the floor. I opened a package with Chinese lettering on the shipping label and unzipped a polybag, inhaling the scent like I was checking for a dirty diaper. “Woof,” I said, handing it to her.

She smelled it. “Ugh, that’s vinyl all right,” she said, recoiling. She gently coughed, covering her mouth. “It’s affecting me,” she said. “I feel it in my chest. I’m getting phlegmy.” Then I remembered. When I had first told her I was writing a book about fashion chemistry, she had shared that she’s sensitive to chemicals and can’t be in places with scented products.

“I’m so sorry!” I cried, hastily gathering up all the bags, throwing them in the bedroom, and slamming the door.

“No, I should have known not to shove my nose in that bag. You don’t react to that?” she asked, still coughing as I opened the windows and flicked on the fan.

“No, I don’t,” I said. “The research says, like, 20 percent of people have chemical sensitivity. That’s not insignificant. But it’s not everyone.” I apologized again and again as her cough persisted over the next fifteen minutes. “No, it will pass,” she said. And eventually it did.

I was surprised that my little experiment—buying an array of items that I guessed were the most toxic available from the most careless brands on the market—had already yielded results, purely by accident. But I wanted to be more scientific. I wanted to have them tested by the most respected lab in fashion chemistry, the Hohenstein Institute in Germany.

Hohenstein does testing for a nonprofit certification you might have heard of, called Oeko-Tex, whose Standard 100 label establishes a standard of safety for consumers. And the limits it sets on how much of each chemical is safe to have on textiles has become a sort of official—if voluntary— guidance for the industry. The question is: can you trust it?

The Gold Standard for Testing and Certifying Non-Toxic Clothing

Oeko-​Tex was created twenty years ago by two European labs, Hohenstein and Testex, as Germany was moving to ban the use of certain azo dyes. It’s an independent nonprofit that certifies brands, suppliers, and their products as safe. (The other label we recommend brands and customers look for is bluesign.)

A thoroughly German organization, Oeko-​Tex takes pride in how strict its tests are—they go way beyond regulations in Europe and the United States, testing for hundreds of substances.

In some of the tests, the material is dissolved completely into a solution and the lab checks how much total of a substance is in there. In other tests, the lab puts a material into a solution that mimics sweat, and then tests the liquid to see how much of a hazardous chemical leached out.

With twenty-​one thousand clients, Oeko-​Tex has massive reach and brand recognition, even if most people have no idea how to pronounce it. (“Oh‑koh tex” is fine.)

Hundreds of thousands of components pass through these labs each year. You’ll see Oeko-​Tex labels on the websites of small start-up brands who were founded on an ethos of sustainability, as well as on sheets and towels sold at large retailers like Target.

The Things That Oeko-Tex Testing Misses

Unfortunately, the call I arranged with an American representative for the German lab Hohenstein did not go as well as I had hoped. We seemed to disagree on some pretty basic assumptions, the most important one being PFAS, the carcinogenic and reproductive toxic class of chemicals that are known as “forever chemicals” because they never break down or go away.

PFAS has been found in Thinx period panties, leading to a lawsuit settlement from the supposedly eco-friendly and healthy women’s-empowerment brand. But Thinx was certified as safe by Oeko-Tex. I asked the Hohenstein rep how that could have happened.

“They may be running tests trying to detect fluorine, but they’re not saying how that fluorine was used,” he said. He asserted that a lot of fluorine does not necessarily indicate PFAS. It is a pretty basic element, after all, added to toothpaste and drinking water as fluoride.

Later, I put this question to Miriam Diamondat the University of Toronto, and she did not agree. “I don’t know who wears shingles as a fashion statement,” she said. “But clothing does not have that level of inorganic fluorine. Fashion is not stuffed with minerals.” While it could show up in makeup, which has minerals like mica to give it sparkle, there’s only one likely reason for high levels of fluorine to be in fashion. In other words, if there is a lot of fluorine on a garment, more than 100 ppm, then it was intentionally put on there by a textile manufacturer. And that means it’s PFAS. Researchers will confirm this by testing for individual types of PFAS.

I suggested to the Hohenstein representative that perhaps the panties contained the type of PFAS that the Oeko-​Tex standard doesn’t test for. There are, after all, more than twelve thousand types of PFAS identified by the EPA (so far—that number keeps going up). While not all of these are chemical products used on fashion—many are the result of others breaking down slightly in the environment, Oeko-​Tex looks for only four dozen of them.

But the Hohenstein rep stuck to his guns. He said it’s hard to come up with new types of perfluorinated chemicals. “That sounds super easy. But it’s not,” he said.

(In January 2024, three years later, Oeko-Tex finally updated its testing to test for total fluorine, like the test that found PFAS in Thinx panties.)

After our contentious call, I wasn’t sure he would still want to help me with my little science project. But it turned out that as long as I promised to him, in writing, that I wouldn’t name and shame any brands based on Hohenstein test failures, the company would assent to working with me. “We want to attract the brands; we don’t want to shame them into working with us,” he said.

I came up with my testing list by choosing brands that don’t have a restricted substance list and aren’t part of any of the organizations that encourage responsible chemistry. I added in a couple of slots for knockoffs and ultra-​fast-​fashion brands that seem to follow me around the internet with their low-​quality banner ads.

My goal was to buy products from brands that the average woman has easy access to, yet that don’t seem to care one whit about their customers’ health. And I was looking for high-​risk products: T‑shirts with printed lettering, neon colors, clear plastic, cheap jewelry, vegan and real leather products, and performance items that promised stain repellency. I bought a dozen items, some of them in twos so I would have enough material to test, and spent about $700 total.

One morning at home, I went through everything at our kitchen table. One mall-brand purchase came with a free-gift bag that had a musky, pungent smell that stung my nostrils and made me sneeze. The long-sleeved surfing top had a smell that nauseated me. “Made in Cambodia,” the tag said. “Keep away from fire.”

The USC Trojans “100% cotton” shirt with gold foil lettering was made in El Salvador. I had leather gloves from a brand that was founded by a famous female designer but sold to a holding company in the early 2000s. It smelled like the interior of a car. A funky (the smell and the style) pair of translucent orange heels had a label that just said “all man-​made materials.” PVC? PU? Who knows! The boys’ school uniform pants were made in Bangladesh and had an accidental poem on their tag: “Stain-​resistant fabric makes spills bead up, roll off / Wrinkle resistant for a neat appearance / Still 100% cotton for comfort.”

When I sent the list to the Hohenstein rep, he warned me, “I’m not sure of your budget, but this will not be inexpensive.” He told me if I was on a budget, I should cut the sandals, surf top, boys’ uniform pants, and the gloves—all from mass-​market mall brands. I had found no indication that they were doing any chemical management, but I figured he knew something I didn’t.

Over the next couple of weeks, he and I sent spreadsheets and emails back and forth, and I got on the phone with him to go over the proposed testing matrix. I had decided I wanted the free-gift bag tested, instead of the actual product I paid for. “Promo is always a problem,” he agreed.

He recommended I test for just a few classes of chemicals per item—things like formaldehyde, heavy metals, restricted dyes, and solvents. The Standard 100 certification would be far more comprehensive. But it could never test for every possible substance using its current methods. He also cut all PFAS testing out, because at the time it was the most expensive type of testing, and he clearly didn’t think it was that important. (In January 2024, three years later, Oeko-Tex finally updated its testing to test for total fluorine, a much more affordable type of test.)

When he sent the final invoice, my jaw dropped. The total cost would be $17,000—42 times more than what I paid for all the products. And that was after I lopped a bunch of stuff off my wish list.

“If I were going to pare things down, I would always choose the things that have plastic,” he said. “I can trim this down. I’ll pick a couple of things I would drop.” A few days later, he sent a new suggested testing matrix. Now it was at $13,000. I cut it down further and made myself a tiny, sad testing list.

Free-gift-​with-​purchase drawstring bag from a mall brand: $1,288

Red-​and-​white cotton, foil-​print collegiate shirt from an online sports store: $2,163

Neon-​orange translucent heels from a mall brand: $2,242

Pink faux-​leather miniskirt from a large Chinese brand: $1,579

Knockoff “Longchamp” bag I bought on Canal Street: $2,366

Total: $9,638

I stared for a long time at the list and the numbers. Two months of New York City living expenses. It was ridiculous. Offensive. How could I possibly justify spending this much money? I stared at the list and the dollar signs some more. Would this provide me with the proof I needed to convince the experts, the brands, and you that the kind of fashion you can buy online and in stores is toxic?

According to Maxine Bédat’s book Unraveled: The Life and Death of a Garment, the Swedish Chemicals Agency (KEMI) has identified twenty-​four hundred textile-​related substances and estimated that 10 percent of them are considered a potential risk to human health. This test would be looking for only half that, especially since I was going the “budget” route and testing only for a few classes of chemicals per item. So even if everything passed, it was no guarantee that it was all actually free of toxic chemicals. What if the pink vinyl skirt, the one that made my friend physically ill, came back with a clean bill of health because we didn’t test for the right substances? It was a huge gamble.

And yet, I wanted to know how this works. Even if all I got from spending almost $10,000 was the insight that this system is laughably out of reach for normal people. I decided that this is what my book advance was for. I wrote back, “Let’s do it.” The Hohenstein rep’s assistant sent me the invoice, and, flinching, I wired the money.

But before I could make it to FedEx, the American Apparel & Footwear Association came out with a report that made my test of the fake Longchamp tote redundant. Out of forty-​seven counterfeit products it had tested, seventeen failed for things like arsenic, lead, and phthalates. One product had six thousand times the limit of cadmium.

I figured I didn’t need more proof that knockoffs are toxic, so I took the faux Longchamp tote out and threw in the leather gloves, and shipped it all off to Germany.

Do You Believe Women, or Textile Limits That Men Have Made Up?

“I am surprised how well the products performed,” the Hohenstein representative wrote three weeks later, attaching a PDF. There were only two official failures. The USC shirt’s foil print failed, with 6.8 ppm over the 10 ppm limit of pentylphenol, a type of alkylphenol that is persistent, bioaccumulative, and toxic. It’s often used in paints and coatings. The gloves, which he had told me weren’t worth testing, also failed with 335.9 ppm of chromium (III)— 136 ppm over Oeko-​Tex’s limit—as well as .29 ppm of nickel and 41.8 ppm of the endocrine disruptor NPEO.

A stinky bag that came free with purchase didn’t fail, but the lab did detect .2 ppm of nickel and .027 ppm of DEHP, a phthalate and endocrine disruptor. A pair of also-stinky orange heels contained formaldehyde and two solvents: DMAc and DMF. Both are classified as reproductive toxins, and the Centers for Disease Control and Prevention (CDC) says that DMF can be absorbed through the skin and is toxic to the liver. Cancer has turned up in workers who were employed in factories with DMF fumes. The CDC also says, “DMF is known to increase the absorption of some substances.” That is, it could interact with other toxic chemicals to make your exposure to it worse. The state of New Jersey’s fact sheet on DMAc says, “High or repeated exposure can affect the brain, causing depression, hallucinations, and personality changes. It also may damage the liver.” But both the substances were under the official limit. So the shoes passed.

The miniskirt that caused my friend’s reaction turned up formaldehyde close to the limit, 9 ppm of antimony, .07 ppm of tetraethyltin, and .01 ppm of DMF. But it technically passed. My friend’s body said one thing. The lab said another. Who would you believe?

“What do you think out of those substances would cause it to stink and then cause a reaction in my friend who smelled it?” I wrote to the Hohenstein representative. “I’m guessing the tetraethyltin, since I see on a hazard sheet it can cause breathing problems and the OSHA limit is .1 ppm over the course of the workday, right above what was in the skirt.” (Repeated exposure to this organotin can also cause brain damage.) I also asked how Oeko-​Tex had come up with those limits. He wrote back trying to calm me down, telling me that I shouldn’t draw any conclusions from the detection of chemicals under the limit or try to figure out where a smell came from.

“Each and every limit established in ST100 (and other standards) are different—sometimes based on data showing a chemical is harmful or can be harmful to a person,” he wrote. “Sometimes that is related to direct skin contact, sometimes inhalation, sometimes they can be based on non-​human studies or even similarities to other molecules structurally.”

Really, the limits that labs use to declare something is safe are often best guesses or just tradition. Almost all the research we have on chemicals comes from factories where employees’ exposure to a chemical over a long period of time can be isolated, measured, and then compared to their rates of serious illness. That’s how we know formaldehyde is linked to cancer: because workers in textile factories that had measurable formaldehyde fumes were shown to be more likely than the average American to develop leukemia.

But to my knowledge, there’s no research on the health effects of wearing a garment with azo dyes, formaldehyde, PFAS, or really anything else that we know is toxic. There’s no information or research on what might happen to my friend should she buy and wear that pink pleather miniskirt to go out dancing every weekend.

And what about the fact that all these chemicals are combined in each piece? I’m not speaking about cutting-​edge science here.

Rachel Carson, in her 1962 book Silent Spring, which led to the ban of the toxic pesticide DDT and the formation of the EPA, wrote, “A human being, unlike a laboratory animal living under rigidly controlled conditions, is never exposed to one chemical alone. . . Whether released into soil or water or a man’s blood, these unrelated chemicals do not remain segregated; there are mysterious and unseen changes by which one alters the power of another for harm.” She goes on to describe several gory examples of dangerous chemical combinations of “safe” products, or so they were considered at the time.

What’s more, only recently did medical research tend to include female humans and animals—scientists feared female hormonal cycles would make the research results messy and skewed. As a result, some medicines have been found to be way too strong for women at what doctors were told was the appropriate dose.

And then there’s the underlying assumption of textile limits: “The dose makes the poison.” Traditional toxicology has always assumed that the smaller the dose, the less the harm. It follows that scientists can always find an amount below which there’s no harm at all. This concept is the premise behind textile limits like Oeko-​Tex’s that say, for example, that anything below .05 ppm is okay when it comes to total phthalates.

But endocrine disruptors are way more chaotic than your typical poison or carcinogen. In fact, an emerging theory is that they follow a dose-​poison U curve: chaotic effects at high doses, more subtle effects at middling doses, and unpredictable, cascading effects again at tiny doses. More and more researchers agree that there is no “safe” dose of endocrine disruptors.

Finally, Oeko-Tex allows disperse dyes in its certified products, which are known immuno- and skin sensitizers, and can cause skin problems in sensitive people. So an Oeko-Tex-certified polyester shirt could still cause a rash or eczema flair.

Protecting Consumers? Or Protecting Brands?

Just a week after I got my test results, a report came out from the modern nonprofit Silent Spring Institute showing that 18 percent of the children’s products it tested, including those labeled as stain resistant, water resistant, and even “nontoxic” and “eco-​friendly,” had PFAS. The brands included Lands’ End, Gap, Old Navy, Children’s Place, and Columbia.

Later that year in the fall, a study came out in Environmental Science & Technology with Miriam Diamond and Graham Peaslee as two leading authors, in which they found that children’s products—mainly school uniforms—marketed in the US and Canada as stain resistant had similar levels of PFAS to outdoor gear. Those brands included Lands’ End. Because I ultimately decided not to have them tested by Hohenstein, I can tell you that the stain-​resistant, wrinkle-resistant boys’ pants I bought were from Lands’ End.

(In January 2024, three years later, Oeko-Tex finally updated its testing to test for total fluorine, just like Peaslee’s test.)

The surf top was from Roxy, the sandals from Skechers, and I also got a purple bra from Lane Bryant. I can’t say whether any of them have restricted substances, because I didn’t have them tested.

I ruminated on the experience for weeks afterward. Why had the Hohenstein rep thrown the big mall brands out of the short list of items to test? He hadn’t thought the gloves were risky at all, and they had failed spectacularly.

At the same time, some Delta flight attendants had posted on Facebook that their new, Oeko- approved uniforms were also causing reactions. In September of 2021, the Association of Flight Attendants, which had been trying to unionize Delta attendants, released the results of the tests it had commissioned on the new, Oeko- certified uniforms.

While these new uniforms were much better than the Passport Plum ones, a pair of men’s “untreated” non- wool pants had tetrachloroethylene (PCE for short) slightly above the Oeko-Tex limit. Two ladies’ scarves that were tested had between two and seven times the recommended limit for chromium. Some of the suit pants and skirts contained tetrachloroethylene (TCE), styrene, and toluene—“all at levels below or barely above the fabric limits.”

For a “normal” person, these uniforms would probably be okay to wear. But it makes sense, given what I had learned throughout reporting the book, that a person who has TILT— who has been overexposed and now reacts to a tiny amount of certain common fashion chemicals— would not be able to wear them without having a reaction.

Delta Air Lines emailed me this statement in October of 2022: “At Delta, the safety and wellbeing of our employees and customers is, and will always be, our number one priority. We are proud to offer our flight attendants a complete collection of untreated, STANDARD 100 by OEKO- TEX® uniform pieces, which means that the pieces have been certified free of harmful substances. At the same time, we are continuing to engage in the accommodation process to provide alternative options for flight attendants with verified medical restrictions.”

It finally occurred to me one night when I was trying to fall asleep that the Oeko-​Tex certification, as strict as it is, ultimately benefits the brands. They’re the ones forking over hundreds of thousands of dollars; they must get some value out of it. They want either to burnish their image as a conscientious and green company or to be protected from financial and legal culpability for toxic chemicals in their products—maybe both. If someone has a reaction to their clothing or finds a toxic substance, the brands can point to the Oeko-​Tex seal—just like the Thinx CEO, Delta, and Lands’ End did—and say, That’s just an individual sensitivity. Or: Our product passed the best test on the market.

But that doesn’t mean you won’t react to an Oeko-Tex-certified product, especially if you’re intolerant or allergic to certain chemicals and dyes, or if you have a chronic condition that flairs with exposure.

The Oeko-Tex Factory Certification

There are similar shortfalls to the Oeko-Tex factory certification. In May 2021 I visited a best-in-class wet processing facility in Tirupur, India, which had an Oeko-Tex certification.

The factory sends their products once a year to Oeko-Tex to be tested for hazardous substances, and they receive a certificate in return. They buy Oeko-Tex-certified chemical products from reputable suppliers and even test the products themselves to ensure they aren’t hazardous.

But there are gaps in this system. The next month on a video call, Ali Abdullah, the founder and managing director at Diamond Denim by the Sapphire Group in Pakistan, told me a story about the time his factory shipped an order of jeans to a brand in Europe. The brand did some testing and found restricted azo dye in the black polyester pockets.

“We traced it down to a supplier of the pocketing. He claimed that the supplier is Oeko-​Tex certified, so there’s no way that there can be azo in there,” Abdullah said. “Three, four years we were buying from the supplier and we never had an issue. And then all of a sudden it comes up, most probably because they were trying to source cheaper chemicals.”

I asked him how that could have happened. “The way the system works for Oeko-​Tex is that every year you send them a fabric to test. You’re not testing each production.” A dyehouse can secretly switch chemicals any time during that year to save money (even though they are supposed to resubmit a new sample for testing). “I have heard many instances of this happening,” he said.

Still the Best Non-Toxic Certification We Have…for Now

Even with all its imperfections, Oeko-​Tex is the best thing we have. And by “we” I mean those of us with the time, money, and education necessary to find safer fashion products. This is a privilege. After all, I was told that the reason none of my items were tested for PFAS was because that test is expensive, and I was on a budget. A tiny $10,000 budget.

If only all Americans and even small brands had the right to know what is in their clothing and choose nontoxic alternatives! But all this testing is done behind the scenes, out of the view of the public, of researchers, of shoppers. If a product fails one of these voluntary tests, it may not get a certificate. But it is a private matter between the brand, the supplier, and the lab, protected by nondisclosure agreements and commercial relationships. That data or information will likely never make it out to the public domain, to governments, to consumers, or to researchers. And technically, there’s nothing illegal about selling adult gloves with excessive chromium or a sweater made with red azo dye, in our land of liberty.

“You have an industry marking their own homework,” says Emily Macintosh, policy officer for textiles at the European Environmental Bureau. “You have certification schemes and, potentially, a revolving door between the people writing the rules and people who are making money out of that same business model. If you don’t make it mandatory for companies to act in a certain way, what we’ve seen is that action is not going to happen fast enough just on the goodwill of industry. I think if we have strong binding rules at the EU level or the global level, it’s going to be much faster than waiting for the so‑called frontliners, or the ‘least-​worst’ actors, to pull the industry up.”

So in conclusion, for now I do recommend the Oeko-Tex certification for shoppers and brands. At the same time, I’m advocating for stronger regulations, including allergy warnings and complete ingredient lists on apparel and shoes so that sensitive shoppers can make the right choice for themselves and their families.