Tumble dryers shed hundreds of tonnes of microfibres into waterways

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

When clothes are washed and dried, they shed tiny particles of clothing fibres. Studies have already shown that vented dryers, which release warm, moist air to the outside via an exhaust pipe, pump out large quantities of airborne microfibres.

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

“They are both generating similar amounts of fibres, but the consequences are very different,” says Neil Lant at Procter & Gamble in Newcastle upon Tyne, UK. “The vented ones are going into the air and the condenser ones are going down the drain.”

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

They found that around 340 milligrams of fibres – a mix of plastic and cotton strands – were released per kilogram of fabric dried. Some of the fibres are captured by the lint filter, while others end up in the condensed water and in the condenser itself.

If those findings are scaled up to reflect dryer use across the UK and the rest of Europe, it means at least 600 tonnes of microfibres are released each year into waterways by tumble dryers. If consumers wash their lint filters under running water, as some manufacturers instruct, that figure could increase by 90 per cent, warns Lant.

Washing machines not fitted with specialist fibre-trapping filters are still a much larger source of fibre pollution than tumble dryers. Lant estimates that the waterborne pollution from a condenser dryer is 25 per cent of the level from the washing machine, per wash load. And because only 15 per cent of washing loads are tumble-dried, the total pollution from washing machines is far greater, estimated at around 13,000 tonnes of microfibre pollution per year across Europe. “We have our priorities right in targeting washing machines first,” says Lant.

In France, all new washing machines must be fitted with microfibre filters from 2025 onwards. Lant says similar legislation “may well be necessary” to force tumble dryer designs to change. “The spotlight has to turn to dryers at some point because it is a big problem,” he says.

In the meantime, the best thing consumers can do if they are concerned about microfibre pollution is to use their tumble dryer less, says John Dean at Northumbria University, UK, who also worked on the study. Lint traps should also be cleared with a vacuum cleaner, with collected fibres disposed of in the bin, he adds.