Biodegradable Shoes: Stella McCartney's Collab With Balena

Every year 22.4 billion pairs of shoes are sold, with a variety of the materials being made with a high environmental footprint, like rubber trainers being made from plastic derived from fossil fuels, according to the WWF.

The National Institute For Health reports that shoe soles are made from harmful chemicals such as zinc, which contributes to the overall chemicals and metals in the environment. 

Stella McCartney has partnered with Balena and Yael Joyc Vantu to create a completely biodegradable shoe sole.

“That balance of true compostability without sacrificing performance simply hadn’t been cracked yet,” says Yael Joyc Vantu, Head of Product at Balena

“Most biodegradable materials on the market just aren’t built to handle the stress, abrasion, and longevity needed in a sneaker sole. 

“That’s where our material came in.”

How is the shoe made?

The soles are named BioCir Flex and are a compostable, recyclable and bio-based alternative for conventional plastics.

The sole has been designed for circularity biodegrading into biomass when composted in industrial facilities. 

“The real hurdle was how to match the durability and flexibility of traditional fossil-based plastics, using a bio-based material that could also break down at end of life,

“Essentially, we created a material that behaves like plastic when you need it, and like nature when you’re done with it,” says Yael. 

Stella McCartney has arranged a recycle system where worn shoes can be sent back to them to be recycled, cutting down on emissions from manufacturing the sole.

It is made from sources like castor beans oils and polysaccharides, that are not widely used as food resources, resulting in little impact on food supply.

BioCir Flex is dyed with cinnamon, a non toxic colourant.

Stella McCartney, founder of Stella McCartney says: “I mean this is insane. My shoe designer came up to me and said, ‘smell the sole’. 

“It is made of cinnamon waste. It smells of cinnamon! 

“And it is basically 100% plant based, recyclable and biodegradable textile.

“It is a closed-loop production, so it ensures completely zero waste. 

"It is mindblowing.” 

What are the struggles when using BioCit Flex?

Thermoplastic Polyurethane which is found in many standard shoe soles is still cheaper than Balena’s new product. 

This will lead to brands deciding whether to take the cost in effort to be more sustainable, something Stella McCartney have said they are willing to do.

“Now it’s about building out robust supply chains and end-of-life systems and having brands prioritise circularity not just for capsule collections, but across their main lines,” says Yael. 

“Regulatory momentum and growing consumer expectations are definitely accelerating that shift.” 

What is Balena?

Balena was established in 2020 to develop high performance bio-based, biodegradable and recyclable materials that are suitable to replace plastics. 

Balena says they are dedicated to creating new materials that responsibly reach its end of life.

With a mission to complete a fully circular process, returning materials to the earth without a negative impact on compost quality, land or seas.

Partnering with industrial compost facilities around the globe to enable the safe decomposition of the materials.

Ines Ribeiro, Head of Product Innovation and Responsible Materials, Stella McCartney says: “I'm so happy to see this finally coming to life, to our stores, to our website.”

“Thank you so much to the Balena team, to David Roubach and Yael Joyce Vantu for your trust, tireless dedication, continuous effort and unshakable determination.

“It is truly inspiring to work with you and to have witnessed your incredible progress up close.

“It is the Future of Fashion!"