The most common microplastics in the environment are microfibers – plastic fragments shaped like tiny threads or filaments. Microfibers come from many sources, including cigarette butts, fishing nets and ropes, but the biggest source is synthetic fabrics, which constantly shed them.
Textiles shed microfibers while they are manufactured, worn and disposed of, but especially when they are washed. A single wash load can release several million microfibers. Many factors affect how many fibers are released, including fabric type, mechanical action, detergents, temperature and the duration of the wash cycle.
My research focuses on coastal ecology and water pollution, including work in New York and New Jersey marshes and estuaries that are heavily affected by human activities. Here are some things to know about reducing microplastic pollution from your washing machine.
Red microfibers collected from coastal waters in a towed sample off Newport, Ore. NOAA Fisheries
From fabric to water and soil
Once garments release microfibers in washing machines, the fibers enter the wastewater stream, which generally goes to a wastewater treatment plant. Advanced treatment plants can remove up to 99% of microfibers from water. But since a single laundry load can produce millions of fibers, treated water discharged from the plant still contains a huge number of them.
Microfibers that are removed during treatment end up in sewage sludge – a mix of solid materials that is processed to remove pathogens. In many cases, treated sewage sludge is applied to soil as a fertilizer. This allows microfibers to enter air and soil, and to be transferred to soil organisms and up the terrestrial food web or taken up by crops.
Textiles are a major source of microfiber pollution, which now is widely distributed throughout the world’s oceans.
Washing more sustainably
Not all fabrics shed microfibers at the same rate. A loosely woven fabric that feels fluffy or fuzzy, such as fleece, sheds more than a tightly woven one. While garments made of natural fibers, such as cotton and wool, would appear to be a solution, unfortunately they also shed microfibers that can pick up pollutants in the environment.
Some textile scientists and manufacturers are developing fabrics that shed less than existing ones, thanks to features such as longer fibers and coatings to reduce shedding. Meanwhile, here are some ways to reduce microfiber shedding from your laundry:
Do laundry less often. Washing full loads instead of partial loads reduces release of microfibers because garments are exposed to less friction during the wash cycle.
Dry laundry on a clothesline. Running clothes in dryers releases additional microfibers into the air from the dryer vent.
Several types of products collect microfibers in the washer before they are released with wastewater. Some are laundry bags made of woven monofilament, a single-polyamide filament that does not disintegrate into fibers. Laundry is washed while enclosed in the bag, which traps microfibers that the garments release. A study of one such product, Guppyfriend, found that it collected about one-third of released microfibers.
Another device, the Cora Ball, is a plastic ball with spines topped with soft plastic discs that capture microfibers. It reduces microfibers by about 25% to 30%, but may not be suitable for loose knits because it can snag on threads and damage clothing.
External filters, like this Samsung version, can be attached to washing machines to remove most microfibers from wastewater. Samsung U.S., CC BY-ND
In a 2021 study, researchers installed washing machine filters in 97 homes in a town in Ontario, Canada, which represented about 10% of the households in the community. They found that this significantly reduced microfibers in treated water from the local treatment plant.
In the U.S., a similar requirement was passed by the California legislature in 2023, but Gov. Gavin Newsom vetoed the bill, saying he was concerned about the cost to consumers. An economic study commissioned by Ocean Conservancy found that filters would increase the price of washing machines by only $14 to $20 per machine. Several states, including California and Oregon, are considering regulations that would require filters in washers.
In my view, requiring manufacturers to add filters that can trap microfibers to washing machines is a reasonable and affordable step that could rapidly reduce the enormous quantities of microfibers in wastewater. The eventual solution will be reengineered textiles, which won’t shed, but it will take some time to develop them and move them into clothing supply chains. In the meantime, filters are the most effective way to tackle the problem.
Judith Weis is affiliated with. Beyond Plastics, Ocean Conservancy
