Reducing Laundry Microfibers: Washing, Drying and Fabric Choices

The problem

Washing synthetic fabrics is a major source of microfibers — tiny polyester and acrylic threads. Park operations produce plenty of laundry: table linens, aprons, towels, uniforms and more.

• In the wash: the churning and vibration of the machine, plus friction between clothes, knock fibers loose into the water.
• In the dryer: dryers release microfibers into the air — a pilot study found dryers release more than washing machines — and dryer vents usually lead outside with little filtering.
• Downstream: the fibers are small enough to go down the drain, through treatment plants and into waterways, where they float. Fish, mussels and clams eat them, ecosystems suffer, and the fibers reach our food and our dinner plates.

Washing

• Add a filter: an external filter on the washer's drain line traps fibers in fine steel mesh. A 2018 University of Toronto and Ocean Conservancy study found one after-market filter caught on average 87% of the microfibers shed by fleece blankets. Other filters go in the drum with the laundry.
• Wash full loads: less room means less friction and less shedding.
• Wash less often — the simplest fix, though not always possible for health and safety reasons.
• Go cold and short.
• Use a front-loading washer if you can.
• Dispose of caught fibers in a sealed, non-recyclable container; microfibers can't be recycled with plastic or aluminum (some companies are working on ways to reuse them).

See also the NPS guidance on laundry practices and water conservation.

Drying

Dryers also use a lot of energy, adding to climate change. To cut energy and microfibers:

• Air-dry when possible.
• Lower the heat and shorten the time.
• Clean the lint filter after every load for better efficiency.
• Skip dryer sheets, which leave residue on the drum and filter; dryer balls separate clothes, improve airflow and shorten drying.
• Install an outdoor lint trap to catch lint and fibers leaving the vent.

More tips: ENERGY STAR laundry best practices.

Materials

Choose natural fabrics — cotton, linen, hemp — over polyester or nylon when you can. Natural fibers still shed, but their fibers do less harm. Polyester is made from petroleum, isn't biodegradable, and takes about twice the energy to produce as cotton.

Sources

Based on "Reducing Laundry Microfibers," National Park Service; a work of the United States government in the public domain. The article's uncredited photograph is left out.