Where the plastic hides in your clothes

Turn your favourite shirt inside out and find the little label. It will tell you, with legal precision, what the fabric is made of. It will not tell you what’s holding the fabric together, what’s been sprayed on it, what the zip is made of, or what it came wrapped in. That isn’t a cover-up. It’s what the rules require, and they don’t require much.

We’ve already covered what happens when synthetic clothes shed fibres in the wash and on your body. This piece is the map: every place plastic turns up in a garment, roughly how much it adds, and what you can do about each. Spoiler: you can avoid most of it, but probably not all of it, and we’ll say so.

What the care label covers, and what it’s allowed to skip

A fibre label is a list of the fabric’s fibres by weight. The fine print decides what counts as “the fabric”.

In the US, the Federal Trade Commission’s textile rules exempt “trimmings” from the fibre count. The list includes labels, waistbands, binding, and “elastic materials and threads inserted in or added to the basic product or garment in minor proportion for holding, reinforcing or similar structural purposes”. Elastic that’s part of the fabric can be left out too, if it covers no more than 20% of the garment’s surface and the label adds “exclusive of elastic”. Any fibre under 5% must be listed as “other fiber”, unless it does a clear job, like the spandex in the rule’s own example, “96 percent Acetate 4 percent Spandex”.

The EU’s labelling regulation (Regulation 1007/2011, as of November 2026) goes further. When the fibre composition is worked out, it leaves out labels and badges, accessories, decorations, “elastic threads and bands added at specific and limited points”, and “stitching and assembly threads”. It also ignores “impregnating products, additional dyeing and printing products”, meaning finishes and prints. For socks, it leaves out the extra elastic yarn in the cuff and the reinforcing yarn in the heel and toe.

And neither label covers anything that isn’t a textile: buttons, zip teeth, snaps, hooks. So “100% cotton” is an honest statement about the cloth. It isn’t a statement about the garment.

The main fabric: polyester, nylon, acrylic and “recycled polyester”

This is the big one, and the good news is that it’s the one you can see. Most of the world’s fibre is now synthetic: Textile Exchange put synthetics, led by polyester, at 69% of the 132 million tonnes produced in 2024. On a label, plastic goes by many names: polyester, nylon (or polyamide), acrylic, spandex (or elastane), polypropylene.

“Recycled polyester” is polyester. US rules define polyester by its chemistry, not where it came from. Recycled fibres were 7.6% of fibre production in 2024, almost all of it recycled polyester, mostly from sources other than old clothes: less than 1% of all fibre came from recycled textiles. Whether bottle-based polyester is still a better choice is a fair question with a long answer, and it gets its own article.

Labels are mostly right about which plastic it is, but not always. When chemists analysed 229 samples from 193 household products labelled polyester (not only clothes; toys too), 87.4% were PET, the usual polyester. Nine samples weren’t polyester at all, and 23 were blends. They found the plasticiser diethyl phthalate in 23.3% of the products.

Viscose, modal, lyocell and “bamboo” fabric are a different case. They’re regenerated cellulose: wood or plant pulp dissolved and spun back into fibre. They aren’t plastic, but how they’re made matters, and that’s a separate article too.

What you can do: read the label before you buy. If a synthetic fibre is the main one, that’s where nearly all the plastic in the garment is.

Stretch: elastane in the fabric, elastic in the waistband

If a fabric stretches and springs back, plastic is usually doing the work. Spandex (the EU’s name for it is elastane) is by US definition at least 85% segmented polyurethane. It turns up a few percent at a time in stretch denim, leggings, T-shirts and underwear.

A waistband can be counted separately, or not counted at all (see the exemptions above). WAMA’s hemp boxer briefs are a rare case that says so plainly: the fabric is “53% Organic Hemp / 44% Organic Cotton / 3% Spandex (Exclusive of the waistband elastic, which is made of natural rubber and nylon.)” Fair Indigo says its waistband elastic is made from synthetic rubber. Kowtow says it uses natural rubber encased in organic cotton instead. Natural rubber is latex, and Canada’s workplace health agency lists elastic in clothing among the products that can contain it, which matters if you’re allergic.

Underwear and socks are the hardest category, and they get their own guide.

What you can do: buy rigid (non-stretch) denim and woven fabrics where you don’t need stretch. For waistbands, drawstrings and button closures avoid elastic altogether. Where you do want elastic, ask the brand what it is.

Finishes the label never mentions

Fabric often leaves the factory with something on it. EU law doesn’t count finishes in the fibre composition, so even a 100% wool or cotton label can hide a polymer coating.

• Machine-washable wool. Wool shrinks and felts in the wash because of the tiny scales on each fibre. To stop it, wool is “frequently shrink-resist treated to make them machine-washable”. The standard method, chlorine-Hercosett, strips the scales with chlorine and then coats the fibre in a polyamide-epichlorohydrin resin. By one review’s estimate, about 70% of wool labelled fully machine-washable is treated this way. The same review warns that coating wool in “non-biodegradable synthetic polymers may affect the biodegradability” of the fibre. Some alternatives still finish with a silicone resin.
• Water repellents (DWR). Water-repellent finishes on outdoor gear are side-chain fluorinated polymers, silicones or hydrocarbons, and the review found impurities or breakdown products escaping from every type. The fluorinated ones are PFAS; see our PFAS explainer for stain-resistant uniforms and what the laws say.
• Softeners. Fabrics are also finished with silicone softeners and coatings. Silicone is a synthetic polymer, though not a conventional plastic; we explain the difference in our silicone guide.
• Wrinkle-free cotton. “Non-iron” finishes aren’t a plastic in the microfibre sense, but they are a chemical resin treatment: the US Government Accountability Office notes that formaldehyde can be used to enhance wrinkle resistance, especially in cotton.

Fibre affects what stays in the cloth, too. In 60 children’s garments bought in Sweden, the most textile chemicals, at the highest levels, were in 100% polyester, and most stayed there after 10 washes. Light-coloured cotton had the fewest. Cotton did let more of what it carried migrate into artificial sweat, about three times as much as polyester. That’s a lab measurement, not a health outcome.

What you can do: “machine washable” on a wool label is a clue that it has probably been shrink-proofed, often with a resin; “hand wash only” wool is more likely to be untreated, though only the brand can tell you. Skip “stain-resistant”, “non-iron” and “easy care” unless you need them, and ask what the finish is.

Sewing thread: the plastic in the seams

The thread holding your cotton shirt together may well be at least part polyester. Coats, a big thread maker, says spun polyester is “one of the most widely used threads”. It says the most common corespun thread has a polyester filament core wrapped in cotton or polyester. The point is strength: polyester holds up under high-speed industrial sewing.

Brands that do disclose are frank about it. Fair Indigo says “We use polyester thread in all our products”, a polyester core wrapped in cotton, because cotton thread is “substantially weaker”. It puts the thread at less than 2% of a T-shirt’s material. Kowtow says it uses organic cotton thread, “replacing the industry-standard polyester cotton thread”.

By weight, thread is small. But every seam has some, polyester is among the most common kinds, and both US and EU rules let it go unmentioned. Even organic certification allows synthetic thread (see below).

What you can do: very little at the shop. Ask the brand. A brand that can name its thread has at least looked.

Zips, buttons, patches, labels and prints

These are small, and the label never mentions them. Most of them have a plastic and a non-plastic version.

• Zips. YKK describes its most popular zip, the coil zipper, as made of “spiral plastic elements, including polyester and nylon”. Moulded-tooth zips are POM resin, another plastic. Metal-tooth zips exist, but the tape they’re sewn to can be cotton or polyester. Arms of Andes, which sells alpaca knitwear, says “our zippers are currently the focus of our plastic reduction efforts”.
• Patches. The “leather-look” patch on the back of jeans may not be leather. Nudie Jeans says its Jacron patch is “made of cellulosic fibers and acrylic polymers”.
• Buttons, snaps and hooks. Buttons can be metal, wood, shell, nut or plastic, and nothing on the label tells you which. Maggie’s Organics says “On our socks, we use plastic tach-its and hooks”, the little fasteners that keep a pair together on the shelf.
• Labels. Labels are exempt from the fibre count in the US and the EU. Kowtow, for one, says its labels are organic cotton. Most brands don’t say.
• Prints. The thick, slightly rubbery print on a T-shirt or team jersey is often plastisol ink. One screen-printing supplier explains that plastisols are “PVC resin (a white powder) and plasticizer (a thick, clear liquid)”, heat-cured onto the fabric.

What you can do: choose button flies, pullovers and drawstrings over zips; metal or natural buttons; and unprinted garments, or ask what the ink is, over thick, plastic-feeling prints.

Packaging: the plastic that comes with the clothes

Even an all-cotton wardrobe usually arrives in plastic. A 2024 study of the clothing industry’s plastic pollution found that plastic waste from cotton clothing is “driven by packaging”, and for wool, silk and other fibres it is “almost entirely due to packaging”. The authors estimated about 1.5 million tonnes a year of packaging plastic leaking into the environment from clothing, out of 8.3 million tonnes of plastic pollution from the industry in 2019. (Three of the authors work for Cotton Incorporated, the US cotton industry’s research and marketing body, and two of them are credited with obtaining the funding, so weigh the cotton comparisons accordingly.)

Brands vary. Kowtow says its packaging is “Containing no plastic”. Cottonique’s paper mailer has an inner lining of “PLA (polylactic acid)”, which it describes as a bioplastic. Maggie’s wraps items in recycled paper “or a bag made from recyclable paper or plastic”. A “compostable” mailer is still a plastic bag, just a different kind, and it usually needs an industrial composter; see what compostable and biodegradable really mean.

What you can do: buy in person when you can and refuse the bag. Online, look for a brand that says what its mailer is made of, and combine orders.

GOTS and OEKO-TEX labels don’t mean plastic-free

These two logos are the most common on “better” clothing. Neither answers the plastic question.

• GOTS certifies organic fibre. Version 8.1 (released June 2026, applying to audits from 1 March 2027) caps all non-organic fibre at 5% in a product labelled “organic”. A product labelled “made with x% organic” can contain up to 10% virgin synthetic fibre such as elastane or nylon, and up to 20% recycled synthetic fibre such as recycled polyester (30% for socks or textile-to-textile recycled fibre). Virgin polyester and acrylic aren’t allowed. For accessories, including sewing thread, elastic, labels and zips, “regenerated or synthetic material” is allowed. GOTS does ban PVC in accessories.
• OEKO-TEX Standard 100 is a test for harmful substances. It says “every thread, button and accessory” has been tested against a list of over 1,000 harmful substances. That tells you about chemical residues. It doesn’t tell you whether those parts are plastic.

Both are worth having for what they cover. Neither covers this.

What we check, and what you can do

Not all the hiding places matter equally. By weight, the main fabric dwarfs everything else: in that 2024 study, discarded synthetic clothing was 81% of the clothing industry’s plastic waste. Stretch fibres add a few percent. Thread adds a little: under 2% of a T-shirt, by one brand’s figure. Trims and finishes add less again, and packaging is outside the garment altogether. We found no reliable figures for how much plastic trims, finishes or mailers add per garment, so we won’t make one up.

Our standard excludes textiles more than 5% synthetic, checked against the maker’s fibre label. Recycled polyester counts as synthetic; regenerated cellulose (viscose, modal, lyocell, “bamboo” fabric) doesn’t. We also ask about the parts the label leaves out: thread, elastic, labels and prints. On a garment whose fibre label is within that 5%, synthetic thread, elastic or a label is allowed at our plastic-minimal tier, but only if the listing names it. A maker who won’t say what the thread is gets it recorded as synthetic. Plastic-free means no plastic in any part, packaging included. That is still a short list. Less plastic, not no plastic.

In order of what makes the biggest difference:

1. Buy fewer new synthetic clothes. Main-fabric plastic is most of the plastic, and it’s printed on the label.
2. Skip stretch where you don’t need it. Rigid denim, woven shirts, drawstring waists.
3. Choose untreated where you can. Wool that isn’t sold as machine washable, no “stain-resistant” or “non-iron” finishes unless you need them.
4. Prefer buttons to zips and plain garments to thick, plastic-feeling prints.
5. Ask the brand about thread, elastic, labels and packaging. A clear answer is a good sign; silence is an answer too.
6. Buy in person or combine orders to cut down on mailers and polybags.
7. Wear what you already own. The clothes already in your wardrobe come with no new packaging and no new plastic. For washing synthetics you already have, see what actually reduces shedding.