The Greener Closet Brief: A Bill to Put a Microplastic Estimate on Clothing Labels

Every week we pick out what's new about what goes into clothes, and we link the original source for each item so you can read it yourself. This week there's a new bill in Congress about microplastic labels, and a crab study where most of the suspected microplastics turned out to be plant fibers, mostly ramie and cotton.

A House bill would put a microplastic estimate on clothing labels

On November 5, Rep. Nancy Mace introduced the Clothing Microplastic Transparency Act of 2026, according to her office's press release. As her office describes it, any company selling clothing would have to put the estimated mass of microplastic in each item on the tag or label. The Federal Trade Commission, working with the EPA, would have a year from the day it became law to write the rules, including one test method every company has to use, and breaking the rule would count as an unfair or deceptive practice under the FTC Act.

It's only just been introduced, so nothing changes on a label yet.

What it means when you shop: until there's a tested number on the tag, the fiber list is the best clue you've got. Polyester, nylon, acrylic and elastane are all plastics. Of the 3,357 products we'd scored by November 6, 1,919 have at least some synthetic fiber, which is more than half, and 721 are synthetic all the way through.

Most of the particles in 52 mangrove crabs were plant fibers, largely ramie and cotton

A study posted as a preprint looked inside 52 swamp ghost crabs collected in 2024 from three mangrove areas in Rio de Janeiro state, Brazil (Xavier et al., 2026). They found 791 particles that looked like microplastics, almost all of them fibers. When they checked them with infrared, most were plant fibers like ramie and cotton, between 72.9% and 81.9% of the particles depending on the site. Synthetic polymers, with polyester the most common, were about 19% of the particles that gave a clear reading. We found this one through The Microfibre Consortium's November newsletter.

What it means when you shop: the abstract doesn't say where those fibers came from, so it doesn't show they came from clothes, but it's a reminder that plant fibers end up inside mangrove crabs too. Cotton and ramie are plant fibers that break down much faster than polyester, which is plastic, and our score counts how long a fiber takes to break down and how much it sheds as two separate factors. Both are explained on how we score.

If you're looking at something right now, paste the link or type what the tag says into the fabric checker and you'll see how much of it is plastic.