The most common synthetic materials in our garments tend to be the most unsustainable but greener alternatives have proliferated.
If the clothing sector were a country, it would have the seventh-largest economy in the world. It has the climate impacts of a major economic power too, contributing 2-4 percent of global carbon emissions, figures comparable to Germany or Russia’s share.
Within this mega-industry, the EU is the leading importer, consuming around a 21 percent share of the world’s total clothing import value per year. A global lifecycle impact assessment shows that Europe’s textile consumption has the fourth highest negative environmental impacts after food, housing, and transportation.
The environmental impacts of European fashion consumption have an indelibly social dimension. Because most of the clothing industry’s carbon emissions are locked up in how materials are cultivated, prepared and processed, the environmental footprint of European garment imports are overwhelmingly concentrated in poorer countries where they are made.
Reducing the harms of the clothing industry will turn on scaling sustainable substitutes for polyester and nylon – the most widely used synthetics in garments. In 2020, almost half of all fibre produced globally was polyester. Nylon is the next most produced single synthetic fibre, making up around 5 percent of the global market.
Polyester and nylon are petrochemical derivatives made by heating and distilling crude oil. The process releases a range of toxic and greenhouse gases including nitrous oxide, a gas with 300 times more warming potential than carbon. Both contribute massively to atmospheric carbon, environmental pollution, and habitat destruction but have proved difficult to recycle.
The quickest route to scaling sustainable substitutes is for retail companies to invest in innovative suppliers.These days, fashion companies seeking sustainable textile replacements face a wealth of choice. Below are bio-based and circular alternatives for the world’s most common oil-based textiles. Each represents an opportunity for retailers to become early movers in their industry’s sustainability transition.
Polyester is as durable and inexpensive as it is environmentally damaging. Its manufacture comes with high carbon emissions and over its product life, the material sheds tiny, non-biodegradable fibres that contribute to microplastic pollution.
Bio-based polyesters reduce manufacturing emissions because their feedstock consists of plant crops or biowaste instead of petroleum. They also tend to be bio-degradable or compostable, meaning that they pose less harm to biodiversity and environmental quality.
DuPont’s industrially compostable polyester replacement Apexa came out in 2017. By contrast to petrochemical polyesters, it is capable of being broken down by microbes into simple carbon dioxide and water. Designed for the textile and packaging markets, it blends with wool, cotton, or cellulose and out-performs other degradable plastics like PLA on durability and heat resistance. Japanese sportswear manufacturer Goldwin is selling products using this fibre.
Fermentation is an increasingly popular approach to bio-based materials manufacture and textiles are no exception. Alt Text, founded in 2019, hit upon a bio-manufacturing method for making polymers similar to polyester using sugars extracted from food waste. In 2021 they bagged a $1.5 million pre-seed round to scale production and commercialise their product. The company has several pilot agreements already to begin in 2022.
Like many other bio-based alternatives to petro-materials, Alt Text’s polyester replacement does have one pitfall from a sustainability perspective. It is classed as an industrially biodegradable material meaning that while it breaks down in specially equipped processing facilities, it will not degrade under natural conditions found in soil and water. The whole-life sustainability of their material will therefore depend entirely on there being effective waste collection procedures and appropriate recycling facilities where the material is disposed of.
Compostable bio-based polyesters, ones that degrade without special treatment, remain a work in progress. Kintra and Pangaia announced a partnership to develop such a material back in 2020 but have not brought it to market so far. In the meantime, recycled polyesters offer a valuable alternative. Made from plastic bottles, packaging, or textile waste, it reduces resource extraction, emissions, and consumer waste pollution in one.
Eco-conscious outdoor clothing brand Patagonia has pioneered the use of recycled polyester since 1993, when they became the first company to make fleece from bottle waste. By their Spring 2022 season, 88 percent of their polyester fabrics were made from recycled materials.
Seattle-based Evrnu is a groundbreaking circular fashion company offering chemical recycling for textile fibres that are difficult to recover with mechanical recycling. Evrnu’s chemical reactions overcomes the challenge of separating fibre blends into their constituent parts without damaging their strength. The company claims that its recovered fibre can be recycled five times without a loss in quality.
Circ, which began as a biofuels company, has come up with a different approach to the problems of blend separation and fibre strength. Their hydrothermal processing method uses water, heat, pressure and chemicals to break down and cleanse fibres, recovering 90 percent of the original components of the garment while maintaining the materials’ functional properties.
DuPont has brought out a biobased alternative to nylon 6 called Sorona made of 37 percent plant-based material produced via fermentation. The bio-manufacturing process for the renewable component sees genetically modified bacteria form PDO (1, 3-propylene glycol) from corn glucose. The PDO is then extracted from the bodies of the microbes into a sticky clear liquid, from which the Sorona fibre is prepared.
Dupont’s Sorona fibre emits 63 per cent fewer greenhouse gases during production. This is not a replica of nylon but a new material that combines nylon’s softness with elasticity and the stain resistance of polyester. It is also easy to dye at low temperature and is colour-fast.
Another chemicals giant to have dived into bio-based nylon development is Solvay. Their product Bio Amni launched June 2021 and will account for 30 percent of the company’s global polyamide portfolio.
In 2020, California-biotech company Genomatica announced the world’s first ton of a key intermediate for nylon-6. Working with their European partner Aquaful, a nylon producer, they developed a fermentation process that turns plant sugars into the target ingredient. The chemical is converted into nylon-6 chips and yarn to be processed by Aquafil at their Slovenian plant. Although Genomatica are keeping the exact intermediate under wraps, it is likely to be caprolactam, a key reactant for nylon-6 production.
Prospects for change
Circularity and bio-based replacements are sorely needed in the EU fashion market. Over the last three decades, unsustainable, poor-quality items with a short product life have dominated consumption patterns. The trend for fast fashion is reflected in how, between 1996 and 2017, EU clothing prices decreased by over 30 percent relative to inflation. The environmental impacts of this are increased landfill waste, increased transportation emissions, and demand for greater resource extraction to replace disposed products.
Since 2020, fashion’s sustainability drive has had to compete with pressures exerted by the Covid crisis. Even online clothing sales declined between 5 to 20 percent across Europe after the start of the pandemic, with overall clothing sales declining between 2 to percent since 2019. China contributed 30 percent of EU clothes imports in 2020 and a supply shock ensued when the country suspended manufacturing to stem the spread of the virus.
Despite these challenges, the highly monopolised character of the EU apparel market means that serious efforts by big brands to source biobased or circular alternatives in key textiles could create sweeping change across the board. Europe’s fashion retail landscape is dominated by five companies: Spain’s Inditex – which owns Zara, Pull & Bear, Massimo Dutti, and others – comes out top, with its 2021 total sales coming out to €27.72 billion. Sweden’s H&M is second, followed by the German Zalando and the UK’s Primark. Sourcing decisions made by any one of the big five can play an instrumental role in accelerating the R&D, scaling, and marketing of renewable materials.
A spectacular example of this came in July 2022. Inditex, Europe’s largest fashion retailer, became one of the investors behind a $30 million funding drive for chemical textile recycling startup Circ. This is the first time that the Spanish brand has invested in a green company. Other retailers have immense reputational gains to make in following their lead.