IT WAS a rookie error. Two decades ago, Gary Cass had just finished a degree in viticulture and was working at a friend’s winery in Western Australia when he forgot to add carbon dioxide to a vat of wine. Oxygen seeped in, feeding bacteria that caused a thick skin of sludge to form on its surface. Grateful not to be sacked, Cass threw it away in disgust. He couldn’t have guessed that, 20 years on, he would be using that same sludge to make more environmentally sound clothes.
Dressing ourselves is a necessity that has spawned one of the most polluting economic activities on the planet. The clothing industry creates carbon emissions of 1.2 billion tonnes a year – more than aviation – and making and maintaining our clothes consumes shedloads of water, energy and non-renewable resources, too. Concern about clothing sustainability is suddenly in vogue. In November 2017, designer Stella McCartney spoke out against her industry following by the sustainable economy think tank the Ellen MacArthur Foundation.
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Cass is just one of many trying to respond to such concerns, finding ways to make clothes greener at all stages of their lives, from production and processing to washing and disposal. And although there is no single easy solution, it turns out there is quite a lot we can all do to help.
Across the planet, more people are wearing more clothes for shorter times. Those garments tend to start their lives in factories in South and East Asia, often far from their end users. Meanwhile, the equivalent of a truckload of clothing is thrown away globally every second, the vast majority ending up either in landfill or being burned.
Most of those clothes are made from synthetic fabrics, above all polyester – essentially plastics made from oil. These materials don’t biodegrade after disposal, but every time they are washed they shed minuscule fibres that pollute rivers and seas (see “Microfibres, megaproblem”).
Cotton and other natural fibres based on plant cellulose do at least break down, but aren’t necessarily any greener. Cotton uses up 2.5 per cent of the world’s arable land and to grow. It also .
Some 10 years ago, Cass was working as a technician at the University of Western Australia in Perth when a chance conversation with Donna Franklin, an artist interested in unconventional clothing, reminded him of his botched wine job. That slimy skin was cellulose, too – cellulose produced not by growing a crop, but simply by bacteria acting on a sugary liquid.
So why not try making a fabric out of that? The encounter led to a collaboration in which Cass and Franklin . One of them was displayed at the World Expo in Milan, Italy, in 2015. They were just curiosities – brittle, and with a limited shelf life. But Cass also founded a company, , to commercialise the idea. In December 2017, the firm announced that it had created rayon fibres from vat-grown cellulose made by feeding Acetobacter bacteria on waste from coconut processing.
These fibres have the potential to be stronger and lighter than their plant-based counterparts, and should feed into the existing industrial process for making viscose, a cellulose fabric produced from wood pulp. “We’re hoping that consumers won’t be able to tell the difference,” says Cass.
Others are pursuing similar ideas. , a company based in California, is using sugar, water and genetically modified yeast to make an artificial silk that is more stretchy and water-resistant than spider silk. is producing clothing fibres from milk proteins, while Italian firm is making textiles from citrus fruit waste. “Lots of people are starting to do this and I think it’s a wonderful thing,” says Cass.
“Ultimately, making clothes greener depends on us changing our own habits”
There is still work to be done before such unconventional fibres can be produced on an industrial scale for a reasonable cost, especially as established players have a huge amount invested in existing production plants, technology and equipment. A quicker win might be to see how current processes could be improved to benefit both producers and the environment.
Danish company is pursuing one option: using more enzymes to increase the efficiency of chemical reactions employed during fabric processing. Some enzymes fill in for bleach to stonewash jeans, for example, while others prevent the formation of unsightly bobbles of loose fibres, or “pills”, on cotton fabrics. The enzymes typically work at room temperature, saving energy, and come from various biological sources. One of the latest anti-pilling enzymes was found in cow dung. “It was like finding a needle in a haystack,” says Christian Wieth of Novozymes.
Other environmentally problematic processes are the waterproofing of outer garments and the colouring of clothes (see “Dye another day”). Waterproofing often uses fluorochemicals, which can have toxic by-products. at the University of Leeds in the UK and his team have found that hydrocarbons, which are relatively innocuous, could work just as well. Unlike fluorochemicals, they aren’t oil repellant, but for most purposes, that doesn’t matter. “If you talk to people who buy outdoor clothing, they don’t want oil repellency,” says Blackburn. “It’s completely over-engineered.”
Ultimately, making clothes greener depends not just on industries changing, but on us altering our own habits, too. We tend to wear garments for less time, disposing of them when they fall apart or go out of fashion – and very little of the clothing we do discard gets reused (see “Want not, waste not”). “All the environmental issues associated with clothing are magnified by that consumption,” says Blackburn. “And it pushes retailers to use cheaper processes and materials.”
In the UK, the non-profit (WRAP) has been working with government and industry since 2012 to That includes encouraging manufacturers to use better-produced cotton and making it clear to consumers that they are
Investing in fewer, more durable garments is one way to reduce resources and waste, as is giving more thought to how we use clothes after purchase (see “Wash yourself green”). Donating used clothing to friends or charity shops rather than just chucking it out also helps. But Wieth thinks consumers need to start making more noise, for example by complaining if their T-shirt starts pilling after a few washes. “Launching a consumer campaign would be a way to create more awareness,” he says.
Want not, waste not
In the UK, almost three-quarters of discarded clothing ends up in landfill or being burned, with less than 1 per cent being recycled into other garments. In part, that’s because recycling clothes isn’t easy. “There is a lack of thought at the design stage, which makes it challenging for recycling to be viable,” says Richard Thompson at the University of Plymouth, UK. Buttons, toggles and other parts have to be removed, but the materials themselves are also tricky to break down and reuse.
That could soon change. A Japanese company called has developed a way to chemically decompose polyester so it can be used again as a raw material, while a European Union-funded project called is investigating how new, high-quality fibres can be created from unwanted clothing. And in 2017, from Aalto University in Finland and his colleagues found an ionic liquid that could be applied to polyester-cotton blends to separate the two types of fibres. Without any further processing, the cotton could then be used to make new clothing.
Dye another day
It is one of the most famous serendipitous discoveries: challenged in 1856 to synthesise the antimalarial drug quinine, 18-year-old chemist William Henry Perkin ended up producing an unknown compound with an intense purple colour. Eventually christened mauveine, this was the first synthetic dye.
Owing to their wide range of hues, resistance to fading and ability for mass production, synthetic dyes have gradually replaced their natural, usually plant-derived, counterparts. But that has come at a cost. Making synthetic dyes uses large quantities of water, energy and chemical salts, and often creates toxic by-products. Widely used azo dyes, for example, are made up of aromatic amines that can harm animals and plants.
One option is to get back to nature. Richard Blackburn at the University of Leeds, UK, and his colleagues have developed techniques that use by-products from food processing. “We’ve been dyeing wool and silk with dyes we extract from blackcurrant waste,” he says. “They make beautiful shades.” The researchers are also looking into how industrial dyeing processes can be made more efficient. By pretreating cotton with a polymer, they were able to eliminate salt from the process, halve water use and reduce the dyeing time.
But it’s not just industrial processes that need scrutiny. Initial tests by a member of Blackburn’s lab show that dye components invisible to the naked eye come off in domestic washes, even after wash cycles. Multiplied by millions of households, the effect adds up. “It’s ironic that there is strict legislation for manufacturers, yet the consumer impact never comes under scrutiny,” says Blackburn.
A radical alternative would be to get rid of dyes altogether. Subtle textures, for instance, could be incorporated into fabrics so hues are produced when they interact with light, rather as butterfly wings are iridescent. “It’s an exciting idea,” says Blackburn. “You could 3D print a colour by creating a specific topography.”
Microfibres, megaproblem
A handful of countries including the US, Canada and the UK have recently enacted bans on microbeads in cosmetics. These tiny plastic pellets slip through sewage treatment processes and contaminate rivers and seas.
Yet according to a 2017 analysis by the International Union for Conservation of Nature, released when synthetic textiles are washed. These fibres could account for over a third of all plastic reaching the open ocean, where their teeny size, typically a fraction of the width of a human hair, wreaks havoc. “Microfibres are so small that even the tiniest animals can take them up,” says from Ocean Conservancy, an environmental charity based in Washington DC.
In 2016, to figure out what influences microfibre shedding, marine biologist at the University of Plymouth, UK, did a load of laundry. The type of fabric was the single biggest factor. “Some garments were releasing about five times more fibres than others in a single wash,” says Thompson. “That’s what surprised me the most.” Acrylic jumpers were the worst offenders, followed by polyester tops and polyester-cotton blends. The kind of washing powder and the water temperature were only minor factors.
Besides changing our clothing and clothes-washing habits (see “Wash yourself green”), there are some quick fixes. Mesh laundry bags designed to catch minuscule escaping threads are already on sale, as are filters for washing machine waste pipes. Another possibility is to protect fabrics with a finishing coating during garment production to limit fibre release. Changes to waste water treatment have also been proposed.
Thompson thinks more research is needed, too, on whether the length of fibres used to make fabrics or the way they are spun into a garment might affect the amount of shedding. “We need to go back to the drawing board,” he says.
Wash yourself green
Laundry habits are often overlooked when considering the environmental impact of our clothes. Analysis undertaken by the Waste and Resources Action Programme in the UK suggests that carbon emissions associated with washing, drying and ironing account for about a third of the lifetime emissions of clothing (see Worse for wear).
Early results from Richard Blackburn’s lab at the University of Leeds in the UK reveal that cutting down on laundering time is the best way to curb water and energy consumption. “I think it’s a learned behaviour that you have to wash your clothes for a long time to get them clean,” says Blackburn. “Nowadays, how dirty are we actually getting?”
To minimise the impact, Christiane Pakula at the University of Applied Sciences and Rainer Stamminger at the Institute of Agricultural Engineering, both in Germany, suggest . Washing powders are now packed with enzymes that can remove most stains at 30°C, says Christian Wieth from Novozymes in Denmark.
Checking the total energy and water use of different machine settings is key. “Eco” cycles often take more time, but may save energy because they soak clothes for longer and so require less mechanical action. A 2016 review concluded that .
Ultimately, though, your best bet is to reduce laundry frequency, especially for outerwear, by simply wearing clothes for longer before washing. That not only saves water and energy, but also extends each garment’s lifetime, while limiting the hazardous microfibres dumped into the oceans. Blackburn says he does his bit – he wears his socks two days running.
This article appeared in print under the headline “Dirty laundry”
