The Clothing Microplastic Transparency Act Would Put Microplastics on Your Clothing Label. Here's What to Know

Every piece of clothing sold in the United States would have to disclose how much microplastic it contains under a bill introduced in the House on Nov. 5.

The measure, the Clothing Microplastic Transparency Act of 2026, was introduced by Congresswoman Nancy Mace of South Carolina. It would require any company that sells clothing to print "the estimated mass of microplastic present" in each item on "a stamp, tag, label, or other similar means of identification."

"Americans deserve to know what is in the clothing touching their skin all day long," Congresswoman Mace said in a statement. "While current labels list fiber content, they do not disclose microplastics. Our bill puts the facts on the tag."

The three-page bill leaves most of the details to federal regulators. The Federal Trade Commission, in consultation with the Environmental Protection Agency, would have one year after enactment to write rules, including a standard test that companies would be required to use to estimate microplastic content. A missing or inaccurate label would be treated as an unfair or deceptive practice under the Federal Trade Commission Act.

The bill defines a microplastic as "a plastic particle that ranges from 5 millimeters to 1 nanometer in size," a span that runs from roughly the width of a pencil eraser to far smaller than the eye can see.

The legislation faces a long path. As of Nov. 5 it had not yet appeared on Congress.gov, which typically posts new bills within a few days, and the draft text released by Congresswoman Mace's office listed no co-sponsors and no committee assignment. Most bills introduced in Congress never receive a vote.

Clothing labels in the United States already carry one kind of disclosure. Under the Textile Fiber Products Identification Act, enforced by the F.T.C., most garments must list each fiber by its generic name and its share of the garment's weight, such as "88% polyester, 12% elastane."

Polyester, nylon, acrylic and elastane, the fiber sold as spandex, are plastics made from petroleum and spun into thread. Polyester alone accounts for about 59 percent of the fiber produced worldwide, according to Textile Exchange, a nonprofit that tracks the industry. In practice, that means the plastic share of most garments is already printed on the label.

What the label does not show is what the fabric releases over its life. Synthetic textiles shed fibers as they are washed and worn. In a 2016 study published in Marine Pollution Bulletin, researchers at the University of Plymouth in England estimated that a single 6-kilogram load of polyester laundry could release more than 496,000 fibers. A 2020 study in Environmental Science & Technology, by researchers in Italy and Britain, found that polyester garments release fibers into the air during ordinary wear in amounts comparable to what they shed in the wash.

Microplastics have since been detected in the human body. In a 2022 study in Environment International, scientists in the Netherlands found plastic particles in the blood of 17 of 22 healthy adult donors. The most common type was PET, the same polymer used to make polyester, though the study could not identify where the particles came from; PET is also widely used in bottles and food packaging. Researchers have not established what health effects, if any, those particles cause or at what levels.

The central question the bill leaves open is what, exactly, the label would measure. Most polyester is produced as long filaments, or as staple fibers cut to a few centimeters, before it is spun into yarn. By the bill's own definition, the intact fiber in a garment may not qualify as microplastic at all. What does qualify are the fragments that break off.

That makes the choice of test method decisive. A test could measure loose fragments already present in a new garment, or the amount a garment sheds over a set number of wash cycles. Laboratory methods for the latter exist: ISO 4484-1, an international standard published in 2023, measures how much material a fabric loses in a controlled wash. The standard itself notes that its results do not directly predict shedding in a home washing machine.

Construction also matters. The 2020 study found that the polyester garment that shed the least was a tightly woven fabric made from long, tightly twisted threads, meaning two shirts with the same fiber label can shed very different amounts. Whether a federal label would capture that difference would depend on rules that do not yet exist.

The bill arrives months after the Agriculture Department began urging Americans to choose cotton over synthetic fabrics, citing concerns about microplastics. That campaign addressed which fibers people buy. The new bill addresses what the tag on a garment must say.

For shoppers, the most direct information remains the fiber content label already sewn into most clothing. Garments made entirely of cotton, linen, wool, silk or hemp contain no synthetic fiber to shed. For synthetics, a 2020 study in PLOS One of real household laundry found that fuller loads and colder, quicker cycles released fewer fibers. Certifications won't fill that gap, because OEKO-TEX doesn't test for microplastics.