A 25C wash is greenest – but can it really clean filthy clothes?
Researchers claim a 30-minute, low-temperature cycle sheds fewer microfibres. Now the onus must be on detergent manufacturers to ensure their products work in colder water
Clothes washed at 25C on a 30-minute cycle shed fewer microfibres into waste water and keep their colour for longer, researchers at the University of Leeds have found. This makes sense. After all, consumers have long been advised by detergent manufacturers and environmental organisations to turn down the dial on the washing machine to 30C. Dropping to 25C is a small adjustment, but possibly a greater psychological one: will clothes really be clean at that temperature, and on such a short cycle?
Lucy Cotton, the report’s lead author, explains that 25C is usually the “inlet” temperature of water in a washing machine – the natural, unchilled and unheated temperature at which the water enters the drum. Her research tested the release of dye and of microfibres from a range of consumer clothing, such as Fruit of the Loom T-shirts. However, the clothes were not dirty when they went into the wash, and only the release of microfibres and desorption of dye were measured. “We weren’t testing for cleanliness,” she says. “One of the things that is useful about this study is that it puts the onus on detergent manufacturers to explore this area. Can they make the cleanliness happen in a cold, quick wash?”