Chemikalien in Kleidung: Kann Polyester die Hormone beeinflussen?

Is polyester an endocrine disruptor? This question has become increasingly relevant because polyester—one of the world’s most commonly used synthetic textiles, accounting for about 70% of synthetic fibers—can incorporate chemicals known to interfere with hormonal systems. Researchers have documented substances such as bisphenol A (BPA), phthalates, and antimony in polyester, highlighting possible routes of human and environmental exposure.

In this post, we’ll examine how polyester is made, what kinds of endocrine disruptors it can carry, and how these substances might migrate into your body through skin contact, sweat, or washing. We’ll also review scientific studies and regulatory insights on polyester’s endocrine-disrupting potential. Finally, you’ll gain simple, actionable steps to protect your health and reduce exposure risks.

Polyester 101: More Than Just “Plastic Fabric”

Polyester is primarily made from polyethylene terephthalate (PET), a type of plastic derived by reacting ethylene glycol with terephthalic acid.1 The PET polymer itself is generally considered inert: in lab tests, its base monomers do not strongly activate estrogen or androgen receptors. However, the true story of polyester goes beyond the polymer.

The Real Concern: Hidden Additives

During manufacturing, finishing, and dyeing, multiple additives can latch onto the fabric—and some of these are suspected or confirmed endocrine disruptors (EDCs).

1. Antimony: The Persistent Catalyst

• Why It’s Used: An antimony compound (antimony trioxide) is commonly used to catalyze PET production. Roughly 80–85% of virgin PET is created with it.

• Hormone Activity: Laboratory studies show 1 µM of antimony trichloride can provoke roughly 50–60% of the estrogenic response generated by 1 nM estradiol in human breast cancer cells.

• Potential Chemical Leaching:  Research by Leonard Sax (2010) connected the leaching of antimony from PET to estrogenic effects seen in bottled water.

Bottom Line: Even though antimony is bound in the fiber, it can migrate under certain conditions, potentially mimicking estrogen.

2. Plasticizers & BPA: Sneaking In Via Coatings

• Phthalates: Although polyester typically needs fewer plasticizers than PVC, phthalates can still enter through blended materials or fabric finishes. A Canadian study discovered 20% of children’s fast-fashion items contained phthalates, lead, and PFAS above safe limits. These plasticizers are known to interfere with hormones.

• Bisphenol A (BPA): A synthetic estrogen found unexpectedly in polyester-spandex apparel. Tests showed up to 19× California’s BPA safety limit in some socks and sports bras. BPA can readily pass through skin, especially under sweaty conditions.

Key Insight: Phthalates and BPA aren’t always obvious in polyester, but small amounts can appear in certain dyes, coatings, or blends, making everyday contact a relevant concern.

3. Dyes & Colorants: Adding More Chemical Layers

Polyester often gets dyed with disperse dyes, which are known for vibrant, long-lasting color. However:

• Benzothiazole (found in certain dyes/finishes) was shown to leach out of fabric, with 62% passing through a simulated skin membrane and 37% absorbed into that “skin” layer after 24 hours.

• Aromatic Amines & Heavy Metals: Some dyes involve these substances, which can be toxic or allergenic, although their direct endocrine activity is less studied.

• Real-World Example: Airline uniforms made from “brightly colored polyester” introduced new wrinkle-resistant and stain-repellent chemicals; employees reported health complaints soon after the switch.

Takeaway: Dyes can host chemicals that penetrate the skin, hinting at yet another pathway for potential EDC exposure.

4. Performance Finishes: PFAS & Other Specialized Treatments

Polyester is frequently coated with special finishes to enhance water-repellency, stain-resistance, or anti-microbial properties:

• PFAS (“Forever Chemicals”): A 2022 study found 65% of tested North American children’s school uniforms—often polyester or poly blends—had concerning PFAS levels.

  • 6:2 FTOH (a PFAS precursor) was the most common, with total PFAS sometimes reaching 153,000 ng/g (~153 ppm).

  • PFAS exposure is linked to thyroid disruption, reproductive harm, certain cancers, and other immune and developmental issues.

• Other Finishes: Flame retardants like PBDEs can disrupt thyroid function; triclosan targets thyroid and estrogen signaling; even silver-based or antibacterial treatments may impact hormone systems.

Why It Matters: PFAS/flame retardants can flake off over time, entering dust, wastewater, and your skin. 

Does Polyester Mess with Hormones?

Chemical Migration and Exposure from Polyester Clothing

Short Answer: They can. Polyester itself isn’t officially classified as an EDC, but it’s frequently loaded with additives (antimony, BPA, phthalates, PFAS, etc.) that are known or suspected hormone disruptors.

Evidence from Research:

• Microplastic Shedding: Washing or wearing polyester fibers releases tiny plastic fibers that may carry attached chemicals. These microplastics appear in oceans, drinking water, and even human tissues.

• Dermal Absorption: Wearing clothing is a form of intimate contact – and indeed, research shows that toxic chemicals from microplastics can be absorbed through skin, but also inhalation, and environmental release. Artificial sweat tests confirm certain toxicants can leach out of polyester and into skin, especially with moisture or friction.

• Cumulative Exposure: Even if each garment’s contribution is small, multiple sources of EDCs can add up significantly over time.

Comparing Polyester to Other Fabrics

By now we know that it’s not the fabric fiber alone, but the chemicals associated with it, that influence hormones. So, which fabrics are more likely to come with those nasty chemicals?

In general, synthetic materials are the ones to watch out for when it comes to hormone disruptors. Synthetic fabrics like polyester, nylon, acrylic, or spandex are generally more susceptible to embedded plasticizers, antimony catalysts, and PFAS finishes than natural fibers (cotton, wool, silk, linen).

Even so, note that any garment can contain EDC-laden dyes or finishes. While no fabric is automatically “chemical-free,” polyester is among the top concerns due to its dependence on petrochemical processes and performance treatments.

On the flip side, natural fibers like cotton, wool, silk, hemp, and linen generally do not contain hormone-disrupting additives in their raw form. A plain cotton or wool garment isn’t made of plastic and won’t shed microplastics or contain BPA by itself. That said, natural fabrics aren’t automatically 100% safe either – they can be treated with chemicals too (pesticides on non-organic cotton, bleaches, dyes, etc.).

But from a hormone disruption perspective, a simple cotton shirt is far less likely to expose you to BPA, phthalates, or PFAS than a polyester shirt. Even medical experts and environmental health organizations encourage choosing natural fibers to reduce exposure to endocrine disruptors in textiles .

In short: plastic-based fabrics (polyester, nylon, acrylic, spandex) are the ones that can indirectly affect hormones due to the chemicals used in them.

If you stick to untreated natural fabrics, you dodge a lot of the health risks. When shopping, keep an eye on labels and marketing terms. “Moisture-wicking,” “fast-dry,” “stain-proof,” etc., often imply the fabric is synthetic and may have chemical enhancements (like BPA or PFAS) to give it those properties . That doesn’t mean you can never wear polyester yoga pants, but it’s wise to be aware and perhaps not make such items the all-day, everyday staples in your wardrobe – especially for children or for clothing that’s in close contact with skin for long periods.

What products have high endocrine disruptors?

Hormone-disrupting chemicals are unfortunately not just in clothing – they’re all around us. You might be wondering if polyester is just one piece of a bigger puzzle. What other products are loaded with endocrine disruptors? Here’s a quick tour of common culprits:

• Plastic Food Containers and Cans: Many plastic food storage containers (the ones without a “BPA-free” label) and the linings of metal food cans can contain Bisphenol A (BPA) or similar chemicals. These can leach into food and drinks, especially when heated.

• Personal Care Products: Ever see “paraben-free” or “phthalate-free” on a shampoo or lotion? Parabens and phthalates are common endocrine disruptors in cosmetics and fragrances. Phthalates often hide under the term “fragrance” in ingredient lists (they help scents last longer). These chemicals can be absorbed through your skin.

• Household Products and Furnishings: Items like vinyl plastic toys (think rubber duckies, inflatable pool toys), vinyl shower curtains, and faux leather furniture often contain phthalates. Older couches or mattresses might have been treated with flame retardant chemicals (PBDEs) that escape into dust and make their way into our bodies. Even certain carpets and floorings have endocrine-disrupting chemicals. In fact, endocrine disruptors are found in so many everyday products – toys, cosmetics, food packaging, carpets, pesticides, you name it – that avoiding them requires a bit of vigilance .

• Thermal Receipt Paper: Those slick receipts from ATMs or stores often use BPA (or a similar chemical BPS) as a developer. If you handle receipts frequently, that BPA can get onto your skin and into your system. It’s a lesser-known source of exposure – one reason some experts say to decline receipts or wash hands after handling them.

• Non-Stick Cookware and Water-Resistant Gear: This is the realm of PFAS, the “forever chemicals.” Non-stick pans (Teflon) and stain-proof or waterproof textiles (jackets, workout leggings, even certain period underwear) may contain PFAS. These chemicals are linked to a host of issues, from thyroid hormone disruption to increased cholesterol and reduced immune responses .

Endocrine disruptors are pervasive in modern products – it’s not just polyester. They hide in plastic containers, processed foods (via packaging), personal care items, household dust, and more.

Cumulative low-dose exposures from multiple sources may influence hormone function and impact human body over time. World Health Organization’s EDC Fact Sheet highlights the importance of reducing overall exposure.

The key is not to panic, but to be informed. By being label-savvy (looking for BPA-free, phthalate-free, etc.) and making small swaps (like using glass or stainless steel for food, choosing clean skincare products, and of course opting for natural fiber clothing when possible), you can cut down a lot on these exposures.

Practical tips moving forward

The thought of your clothes messing with your hormones can feel overwhelming. But you have control over what you wear and how you manage your exposure. Now that you’re informed, you can take simple, meaningful steps to protect yourself and your family.

Remember, Knowledge is power, and small changes add up! Consider these steps to reduce the risk of endocrine disruptors from clothing and beyond:

• Choose Natural, Organic Fabrics Whenever Possible: Favor clothes made from organic cotton, bamboo, hemp, wool, or silk – ideally organic or OEKO-TEX® certified.

• Look for Certifications: Labels like OEKO-TEX Standard 100 or Bluesign reduce the likelihood of harmful additives. Certifications like GOTS (Global Organic Textile Standard) even ban the use of toxic flame retardants and PFAS in production

• Be Picky with Performance Gear: If you need that waterproof jacket or stretchy yoga set, shop around for brands that disclose their chemistry. Many outdoor brands now have lines that are PFAS-free or use safer alternatives. Look for words like "non-toxic Activewear", “PFAS-free DWR” or “eco-finish.” For activewear, consider natural fiber options (there are merino wool workout clothes that wick sweat without any chemicals!). And if you do buy polyester/spandex activewear, wash it a few times before heavy use (to remove surface chemicals), and avoid wearing it for very long periods next to your skin if possible.

• Wash and Ventilate New Clothes: Make it a habit to wash new garments before the first wear. This helps rinse out surface chemicals like excess dyes or finishes. Use a fragrance-free, gentle non toxic detergent (some regular detergents have endocrine disruptors like phthalates in synthetic fragrance ). Also, airing out new clothes (especially if they have a strong chemical odor) can help reduce any volatile compounds. It’s a simple step that can make a difference in what your skin absorbs.

• Use Microfiber Filters or Bags: To tackle the microplastic shedding issue (and protect the environment as well as your health), consider using a microfiber-catching laundry bag or filter. Products like the “Guppyfriend” washing bag or lint filter devices for washers can catch a lot of those fibers before they go down the drain. Less shedding means fewer microplastic particles carrying endocrine disruptors into waterways – and potentially into your home’s air and dust. It’s an easy way to cut down on the hidden pollution from washing synthetics.

• Avoid “Chemical” Marketing Terms: As mentioned, clothes marketed as “stain-resistant, wrinkle-free, antimicrobial, ultra-fast-dry, anti-odor,” etc., often owe those claims to chemical treatments. If you don’t truly need those features, skip them. For instance, instead of no-iron treated shirts, buy shirts in a fabric that naturally doesn’t wrinkle as much (or just iron when needed). Rather than anti-odor gym shirts (which might use antimicrobials that could be hormone disruptors), you can wash your workout gear more often or use odor-absorbing baking soda in the wash. It sounds old-fashioned, but it cuts out a potential source of toxins.

Finally, remember that stress can also mess with hormones – and stressing over toxins can become counterproductive. The goal isn’t to panic or feel helpless; it’s to make informed choices one step at a time. Swap out a few polyester items for cotton or linen. Invest in a couple of high-quality basics that are sustainably made. Over time, these changes not only reduce endocrine disruptor exposure, but also often lead to a more eco-friendly and skin-friendly wardrobe.

And hey, if you found this helpful, consider sharing it with a friend who might be curious about why their workout shirt smells like chemicals or why their dermatologist asked about polyester. We’re all learning and doing our best to stay healthy in a complex world.

Key Takeaways

• Polyester Additives: Chemicals like antimony, BPA, phthalates, and PFAS often end up in polyester during manufacturing and finishing.

• Hormone Disruption: These additives may act as endocrine disruptors, affecting hormones involved in growth, reproduction, and metabolism.

• Exposure Pathways: Sweat, friction, and washing can release microfibers and chemicals, potentially reaching your skin or the environment.

• Safer Alternatives: Opting for natural fibers (or PFAS-free certifications) and washing new garments first can reduce exposure risks.

• Simple Solutions: Microfiber-catching laundry bags, reading labels, and avoiding “stain-proof” or “anti-odor” finishes can help you avoid unnecessary toxins.

Is polyester an endocrine disruptor? Polyester itself—made from PET—doesn’t automatically disrupt hormones. However, the cocktail of antimony, plasticizers, BPA, PFAS, and other finishes frequently embedded in or on polyester can introduce real endocrine risks. These chemicals can migrate to skin, shed through microfibers, or accumulate in dust and waterways, raising concerns about long-term and combined exposures.

You you are looking to minimize potential endocrine disruption from clothing, you might opt for natural fiber garments without specialty finishes, or seek out polyester garments certified to be free of harmful substances. Washing new clothes before first use can remove some surface chemicals (though it won’t eliminate embedded ones like antimony).

By staying informed and reading labels, you can significantly reduce your risk of exposure to hidden hormone disruptors lurking in synthetic apparel.

FAQ to Polyester and Endocrine Disruptors

What plastics are endocrine disruptors?

Several common plastics contain chemicals that act as endocrine disruptors, with BPA (found in polycarbonate plastics) and phthalates (used in PVC) being among the most well-documented. Polystyrene (containing styrene) and plastics with flame retardants like PBDEs can also disrupt hormone function in the human health. These endocrine-disrupting chemicals can leach out over time, especially when exposed to heat, UV light, or acidic conditions.

Does polyester emit toxins?

Polyester can release small amounts of chemicals like antimony (used as a catalyst during manufacturing) and formaldehyde (from certain fabric finishes), particularly when exposed to heat or extended wear. During washing, polyester sheds microplastic fibers that contain these compounds and can potentially carry other adsorbed chemicals. While the health impacts of these emissions at typical exposure levels are still being studied, those with chemical sensitivities may experience irritation or reactions to polyester fabrics.

What fabrics affect hormones?

Synthetic fabrics like polyester, nylon, and acrylic may contain residual chemicals from manufacturing that have hormone-disrupting properties. Conventionally grown cotton can contain pesticide residues with endocrine-disrupting effects, while fabrics treated with stain-resistant, water-repellent, or wrinkle-free finishes often contain PFAS or formaldehyde-releasing compounds that may interfere with hormonal systems.

Does polyester have PFAS in it?

Polyester itself (the polymer polyethylene terephthalate) does not inherently contain PFAS in its chemical structure. However, many polyester products, especially those marketed as water-resistant, stain-resistant, or outdoor performance fabrics, are treated with PFAS compounds to achieve these properties.

Is polyester PFAS free?

Basic, untreated polyester is typically PFAS-free in its raw form, but many finished polyester products receive PFAS treatments for water and stain resistance. To ensure PFAS-free polyester, look for products explicitly labeled as PFAS-free or those certified by standards like OEKO-TEX or GOTS, which limit or prohibit these chemicals.