Global footwear consumption is projected to grow by more than 5% per year and reach 40 billion pairs in 2025. The production of shoes has significant environmental impacts, due to the use of materials such as leather, adhesives, rubber, polyvinyl chloride (PVC) and polyurethane (PU). And after we are done using them, most shoes end up on landfills.

The vegetarian and vegan communities were among the first to favour animal- and environmentally-friendly footwear. Initially, eco-shoes tended to be low-quality, unattractive and difficult to find. This prohibited a wider spread, because when it comes to buying a new pair of shoes, consumers often look for the most stylish and comfortable pair they can find. However, nowadays conscious consumption is hip and dedication to locally grown, pesticide free, and handmade products has grown into one of the most sophisticated and highly influential markets in the world.

Shoes are normally made from a mixture of different materials, such as textiles, plastics, elastomers (elastic polymers like rubber) and leather. Leather, rubber, and many textiles are already bio-based – made from organic matter. But plastics and non-rubber elastomers are generally derived from petrochemicals, as are some man-made textiles. The use of sustainable materials for footwear production has been expanding in the last 25 years or so. Nowadays, all shoe parts can be made from bio-based materials. The upper can be made from organic cotton, synthetic silk biopolymers, and Piñatex (made from pineapple leaf fibres). Soles can be produced from natural latex, coir (a mix of coconut husk and natural latex), cork or corn, and insoles from castor oil. Harder parts, for example in mountaineering shoes, can be made from bio-based polyamides or biobased thermoplastic polyurethane (TPU). And finally, complete shoes can now be produced from algae-based foam and slippers from palm leafs.

When developing new products, footwear manufacturers look at all three phases of the product lifecycle. First, they can improve the production, where materials that can be replenished can replace petroleum-based materials commonly used today. Second, they consider the use phase: when the product hits the market, consumers don’t want to sacrifice on how shoes look and perform. Third, they think about what happens to shoes when people are done wearing them. Bio-based materials can offer advantages to all three phases. They are renewable and can provide comparable or even enhanced performance. Some materials are lighter and others can provide a unique combination of characteristics, like a combination of rigidity and flexibility and reduced moisture uptake. And finally, bio-based footwear can be compostable or even biodegradable.

Biodegradable footwear is footwear that uses biodegradable materials that can compost after disposal. Such materials can include both natural and synthetic biodegradable polymers and offer a long-term solution to landfill pollution. Recently various large sportswear industries have announced the market introduction of fully biodegradable high-performance athletic footwear. Another trend in the eco-shoe-world is the use of recycled materials, for example plastic gathered from the plastic soup in our oceans. All of these trends – bio-based, biodegradable and recycled shoes – contribute to a circular economy: they reduce the use of fossil materials and avoid piling up ever more waste.

 

Photo credits: Dương Trãn Quõc

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14/08/2017