Cirql®, a leader in sustainable materials for the global footwear industry, introduces its second new material introduction in the past month with Cirql Zero 36™ midsole foam. Footwear brands focused on lowering their environmental impact and meeting increasingly strict regulatory guidelines now have a new bio-based, biodegradable option to replace traditional plastic midsole foams.
Cirql Zero36 midsole foam is made from 36% bio-based content and is fully biodegradable via industrial composting at the end of useful life. It is manufactured using a patented, chemical-free supercritical foaming process, which can be deployed by any Tier 1 facility that’s equipped with autoclave foaming technology.

With a low density and uniform microcellular composition, Cirql Zero36 is a high-energy, comfort-forward foam that’s resilient and durable. It’s ideally suited to replace EVA in a midsole application.

This is the latest material innovation serving Cirql’s mission to help footwear brands reach their own climate and sustainability goals. Cirql’s commitment is to offer trusted, scalable footwear material solutions to keep shoes out of landfills.

“We recognize that our brand partners need options that satisfy many requirements: performance, comfort, regulatory needs, scalability, climate goals and supply chain transparency, among others,” said Matt Thwaites, Vice President and General Manager of Cirql. “Our aim at Cirql is to create products that make it easy for footwear brands to meet those needs, while simultaneously building a lower impact industry and a more circular future for all footwear.”

Cirql Zero36 is third-party tested and is available as a finished component or polymer. The technology is backed by 25 patents issued worldwide, with dozens more pending.

The Cirql product lineup comprises materials that are either recyclable or biodegradable via industrial composting at the end of life. In September 2025, Cirql rTPU50 expanded the brand’s offerings of GRS-certified, fully recyclable midsole foams. Cirql Zero debuted in December 2024 and won the ISPO BrandNew Award for Sustainability. Cirql Zero36 is the newest EVA-alternative in the esteemed “Zero” category.