The research published in ACS Environmental Science & Technology Water, finds handwashing clothes reduces microplastic pollution and is “environmentally

Previous research has shown microplastics (tiny plastic particles or fibres smaller than 5mm in diameter) are released when clothes are machine-washed. These can end up in wastewater and the environment.

Last year a report on sustainable textiles from the Monash Sustainable Development Institute noted 35% of microplastic ocean pollution comes from washing textiles.

Yet handwashing, which remains common practice in many parts of the world, has received comparatively little research attention, the paper from the American Chemical Society notes.

To investigate, the research team cleaned 15 x 15cm fabric swatches of 100% polyester knit and a 95% polyester/5% spandex blend. They used different methods of hand washing in a stainless steel basin and machine washing in a top-loader. The washing and rinsing liquid was collected, filtered, dried and photographed.

When washed by hand, the polyester fabric released 1,853 microplastic pieces on average. This was far fewer than the 23,723 microplastic pieces released when the same fabric was machine washed.

The size of microplastic fibres released in handwashing was longer on average (258 μm) than machine-washing (155 μm). One micrometre (μm) is equivalent to 0.001 millimetres.

While adding detergent, pre-soaking and using a washboard increased the quantity of microplastics released during handwashing, the amount remained less than using a machine.

The study shows the release of microplastic fibres decreases over sequential wash cycles for both machine and hand washing. In contrast, altering the temperature, detergent type, wash time, and amount of water for handwashing had little impact on microplastic pollution.