Bridge of Weir Leather—a supplier of locally sourced, low-carbon leather to the luxury automotive sector—has unveiled BioPRO, a next-generation, protein-based molded seat foam that offers a lower-impact alternative to traditional foam, company officials stated in a press release.
BioPRO contains 20% protein-content, a by-product of Scottish Leather Group’s (SLG) manufacturing process, and is formulated to replace harmful chemicals such as melamine, bromine, titanium phosphate, graphite and PFAS.
The foam supports automotive manufacturers in reducing fossil-derived content, improving circularity and lowering life‑cycle impact, noted the release. The protein-based BioPRO is a recoverable, truly circular and sustainable material. At the end of a foam’s life in a car, the material can be recovered through an acidolysis process, creating future potential for its constituent elements to be reused.
Performance & Design Benefits for Auto Interiors
It also offers enhanced flexibility for interior development, allowing seat properties and comfort levels to be fully tailored, the company said. BioPRO’s engineered consistency and customizable comfort offer greater design freedom to premium and performance-led brands seeking differentiation within the cabin. Each foam is molded to an exact specification, delivering a precise fit and eliminating the material waste associated with conventional cut foams, which often require multiple parts and increase overall weight.
Originally launched for the aviation sector by Muirhead, a sister company within SLG, BioPRO has already been recognized on the global stage with a nomination for the Earthshot Prize. SLG says its introduction into automotive reinforces its leadership in responsible interior materials.
“For decades, we have been proud to support our automotive partners as they work to reduce the environmental impact of their interiors. BioPRO is the next step in that journey,” said James Muirhead, Scottish Leather Group CCO. “It reflects years of commitment from our innovation team and a shared ambition with our customers to move away from fossil-derived content while maintaining the quality and comfort they expect.
“Developing more responsible material solutions is a key priority across the group, as demonstrated by the new tanning technologies that we introduced in 2024. With BioPRO being fully recoverable at end of life, it enables new pathways for seat components without compromising durability. It represents a meaningful advancement in supporting more sustainable automotive interiors.”
Weight, Fire Resistance & Safety Specs
With a base density beginning at 47 kg/m³, BioPRO offers weight-saving advantages while maintaining comfort and long-term performance. Its natural intumescent, fire-resistant properties meet stringent automotive safety requirements, without the need for additional fire‑retardant treatments.
Bridge of Weir says its leather continues to be chosen by the world’s leading luxury automotive manufacturers, including Aston Martin, McLaren, JLR and Polestar, recognized for its quality, durability and industry-leading environmental performance.