Should clothes be worn only once and then washed?

The French government-backed Agency for Ecological Transition (ADEME) recommends wearing T-shirts five times, jeans 30 times, and gym clothes three times before washing.

This rule has faced strong opposition due to concerns about hygiene, especially with gym clothes that accumulate a lot of bacteria.

However, experts say it's time to change the perception of cleanliness and admit the agency has a point.

The environmental impact of doing laundry is staggering. Every year, washing machines worldwide emit around 62 million tonnes of CO2. In Europe, 60% of CO2 is produced by heating water during laundry.

It’s not just carbon emissions. When you wash clothes, the friction in the drum causes the fabric to shed tiny microfibres. “Some fabrics, especially synthetics, are particularly susceptible to this,” says Sajida Gordon, a lecturer and researcher at Nottingham Trent University.

Studies show that polyester, felt and acrylic release the highest amount of microfibres per wash. In 2016, researchers at the University of Plymouth in the UK found that just one wash of polyester clothing can release up to 700,000 microfibres. These are so small that they pass through wastewater treatment systems and end up in rivers and oceans, harming ecosystems. They can be ingested by marine life and accumulate in the food chain, meaning that if fish eat them, humans will eat them.

In addition, detergents also have negative impacts on the environment, causing ecological imbalance and increasing CO2 levels.

Even when people are aware of these issues, they are still reluctant to change their laundry habits. Last year, a study from Chalmers University of Technology in Sweden found that fear of being perceived as unhygienic often outweighs environmental concerns.

In fact, washing clothes too often can also cause them to wear out faster. Worn-out clothes contribute to the huge amount of waste generated by the fashion industry.

So how can we reduce the number of washes without making others uncomfortable? Stylist Lindsay Edwards (UK) recommends a trick to avoid the habit of throwing clean clothes in the machine: smell them with your nose.

“If the clothes still smell fresh and look clean, hang them back in the closet,” she suggests.

Hygiene expert Heidi Phillips also says that if you don't work in an environment that gets dirty easily or accidentally spill something on your clothes; if you shower regularly and use deodorant to reduce sweating, you can wear an outfit at least twice before needing to wash it.

Of course, underwear is the exception, as it absorbs a lot of body oils, sweat, and dead skin cells. "A sweater or cardigan can be worn four to five times if you wear a bra," Heidi adds.

However, she disagrees with the French agency's recommendations on workout clothes. "Gym clothes need to be washed after every wear," she asserts. "They absorb a lot of sweat when exercising, while synthetic fibers, which retain moisture well, create an ideal environment for bacteria to grow."