Dryers dump hundreds of tons of microfibers into waterways

All tumble dryers release significant amounts of microfibers into the environment, research has revealed, putting new pressure on manufacturers to redesign their appliances.

When clothes are washed and dried, they shed small particles of clothing fibers. Studies have already shown that vented dryers, which release warm, humid air outside through an exhaust pipe, pump out large amounts of airborne microfibers.

Now a new study suggests that condenser dryers, which condense moist air into water and store it in a chamber inside the appliance, produce similar amounts of microfiber pollution, which ends up in waterways.

“They both generate similar amounts of fiber, but the consequences are very different,” says Neil Lant of Procter & Gamble in Newcastle upon Tyne, UK. “The ventilated ones go into the air and the condenser ones go down the drain.”

Lant and his colleagues evaluated the performance of condenser tumble dryers, which are popular in the UK and Europe thanks to their lower energy demand, by testing how many microfibers were shed from test loads of new, clean garments and soiled laundry from volunteer homes in Newcastle.

They found that about 340 milligrams of fibers, a mixture of plastic and cotton threads, were released per kilogram of dry cloth. Some of the fibers are caught by the lint filter, while others end up in the condensed water and in the condenser itself.

If those findings are extended to reflect the use of tumble dryers in the UK and the rest of Europe, it means that tumble dryers release at least 600 tonnes of microfibres each year into waterways. If consumers wash their lint filters under running water, as some manufacturers suggest, that number could increase by 90 percent, Lant says.

Washing machines that are not equipped with special filters to catch fibers are still a much greater source of fiber contamination than dryers. Lant estimates that waterborne contamination from a condenser dryer is 25 percent of the washing machine level, per wash load. And because only 15 percent of laundry loads are tumble dried, the total contamination from washing machines is much higher, estimated at around 13,000 tonnes of microfiber contamination per year across Europe. “Our priorities are right to target washing machines first,” Lant says.

In France, all new washing machines must be fitted with microfiber filters from 2025. Lant says similar legislation “may well be necessary” to force changes to dryer designs. “The spotlight has to be on the dryers at some point because it’s a big problem,” he says.

In the meantime, the best thing consumers can do if they’re concerned about contamination from microfibers is to use their dryer less, says John Dean of Northumbria University, UK, who also worked on the study. Lint traps should also be cleaned with a vacuum, and the collected fibers should be disposed of in the bin, he adds.