The most common synthetic materials in our clothing tend to be the least sustainable alternatives, but greener alternatives have proliferated.

If the apparel industry was a country, it would have the seventh largest economy in the world. It also has the climate impacts of a major economic power, contributing 2-4% of global carbon emissions, figures comparable to the share of Germany or Russia.

Within this mega-industry, the EU is the largest importer, consuming around 21% of the total value of global clothing imports per year. A comprehensive life cycle impact assessment shows that textile consumption in Europe has the fourth negative impact on the environment after food, housing and transport.

The environmental impacts of European fashion consumption have an indelible social dimension. Since most of the clothing industry’s carbon emissions are linked to the way materials are grown, prepared and processed, the environmental footprint of European clothing imports is massively concentrated in the poorest countries where they are made.

Reducing harm from the apparel industry will come through scaling up sustainable substitutes for polyester and nylon – the most widely used synthetics in clothing. In 2020, nearly half of all fibers produced globally were polyester. Nylon is the second most produced single synthetic fiber, accounting for around 5% 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 a warming potential 300 times that of carbon. Both contribute massively to atmospheric carbon, environmental pollution and habitat destruction, but have proven difficult to recycle.

The fastest route to developing sustainable substitutes is for retail companies to invest in innovative suppliers. These days, fashion companies looking for sustainable textile substitutes are faced with a multitude of choices. Below are bio-based and circular alternatives for the world’s most common oil-based textiles. Each represents an opportunity for retailers to become the first movers in their industry’s sustainability transition.

Polyester

Polyester is as durable and inexpensive as it is harmful to the environment. Its manufacture comes with high carbon emissions and over its lifetime the material sheds tiny non-biodegradable fibers that contribute to microplastic pollution.

Bio-based polyesters reduce manufacturing emissions because their raw material is made from plant crops or bio-waste instead of petroleum. They also tend to be biodegradable or compostable, meaning they are less harmful to biodiversity and environmental quality.

DuPont’s industrially compostable polyester replacement Apexa was released in 2017. Unlike 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 outperforms other degradable plastics like PLA in durability and heat resistance. The Japanese sportswear manufacturer Goldwin markets products using this fiber.

Fermentation is an increasingly popular approach in the manufacture of bio-based materials and textiles are no exception. Alt Text, founded in 2019, discovered a biofabrication method to make polyester-like polymers using sugars extracted from food waste. In 2021, they bagged a $1.5 million pre-seed round to ramp up production and bring their product to market. The company already has several pilot agreements due to begin in 2022.

Like many other bio-based alternatives to petro-materials, replacing polyester with Alt Text presents a pitfall from a sustainability standpoint. It is classified as an industrially biodegradable material, which means that although it breaks down in specially equipped treatment facilities, it will not degrade under natural conditions found in soil and water. The lifetime durability of their material will therefore be entirely dependent on the existence of effective waste collection procedures and appropriate recycling facilities where the material is disposed of.

Compostable bio-based polyesters, those that degrade without special treatment, remain a work in progress. Kintra and Pangaia have announced a partnership to develop such material in 2020, but have not yet brought it to market. In the meantime, recycled polyesters offer an attractive alternative. Made from plastic bottles, packaging or textile waste, it reduces both resource extraction and emissions and pollution from consumer waste.

Eco-friendly outdoor clothing brand Patagonia pioneered the use of recycled polyester since 1993, when it became the first company to make fleece from waste bottles. In their spring 2022 season, 88% of their polyester fabrics were made from recycled materials.

Seattle-based Evrnu is a revolutionary circular fashion company that offers chemical recycling of hard-to-recover textile fibers with mechanical recycling. Evrnu’s chemical reactions overcome the challenge of separating fiber blends into their components without damaging their strength. The company claims that its recovered fiber can be recycled five times without loss of quality.

Circ, which began as a biofuels company, offered a different approach to the problems of blend separation and fiber strength. Their hydrothermal treatment method uses water, heat, pressure and chemicals to break down and clean the fibers, recovering 90% of the garment’s original components while maintaining the materials’ functional properties.

Nylon

DuPont has developed a bio-based alternative to Nylon 6 called Sorona, which is made from 37% plant material produced by fermentation. The renewable component’s biomanufacturing process sees genetically engineered 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 fiber is prepared.

Dupont’s Sorona fiber emits 63% less greenhouse gases during production. It is not a replica of nylon but a new material that combines the softness of nylon with the elasticity and stain resistance of polyester. It is also easy to dye at low temperatures and is unalterable.

Solvay is another chemical giant to have embarked on the development of bio-based nylon. Their Bio Amni product was launched in June 2021 and will represent 30% of the company’s global polyamide portfolio.

In 2020, California-based biotech company Genomatica announced the world’s first ton of a key nylon-6 intermediate. Together with their European partner Aquaful, a nylon producer, they have developed a fermentation process that transforms plant sugars into the target ingredient. The chemical is converted into nylon-6 shavings and yarn for processing by Aquafil at its Slovenian plant. Although Genomatica keeps the exact intermediate a secret, it is likely caprolactam, a key reagent for the production of nylon-6.

Prospects for change

Circularity and bio-based substitutes are essential in the EU fashion market. Over the past three decades, non-durable and low-quality items with a short lifespan have dominated consumption patterns. The fast fashion trend is reflected in how between 1996 and 2017 clothing prices in the EU fell by more than 30% 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, the dynamics of sustainable fashion development must compete with the pressures exerted by the Covid crisis. Even online clothing sales fell by 5-20% across Europe after the start of the pandemic, with overall clothing sales down 2-10% since 2019. China contributed 30% of imports clothing from the EU in 2020 and a supply shock occurred when the country suspended manufacturing to stem the spread of the virus.

Despite these challenges, the highly monopolized nature of the EU clothing market means that serious efforts by big brands to find bio-based or circular alternatives in key textiles could create a sea change at all levels. Europe’s fashion retail landscape is dominated by five companies: Spain’s Inditex – which owns Zara, Pull & Bear, Massimo Dutti and others – tops the list, with its total sales in 2021 amounting to 27.72 billion euros. The Swedish H&M is second, followed by the German Zalando and the British Primark. Sourcing decisions made by any of the Big Five can be instrumental in accelerating the R&D, scale-up and commercialization of renewable materials.

A spectacular example of this happened in July 2022. Inditex, Europe’s largest fashion retailer, became one of the investors behind a $30 million fundraising campaign for the startup. of chemical recycling of textiles Circ. This is the first time that the Spanish brand has invested in a green company. Other retailers have huge reputational gains to make by following their lead.