Only one out of the world’s 12 major tire manufacturers have shown evidence their supply chain is deforestation-free, a recent assessment has found.

The report, released March 26 by the Zoological Society of London (ZSL), assessed 30 natural rubber companies, including 12 that manufacture tires, to see what portion of their supply chain is independently verified as deforestation- and conversion-free (DCF). These companies collectively manage at least 1.4 million hectares (3.5 million acres) of tropical forest landscapes.

Report co-author Sam Ginger, a sustainable business specialist at ZSL, told Mongabay by email that having a third party independently verify their information is key to ensuring what they’re saying is true.

ZSL’s assessment found that only four natural rubber companies published some evidence of monitoring deforestation in the operations of their suppliers. Among the tire companies, only the French giant, Michelin, used a third-party to independently evaluate 9% of its supply chain.

A Michelin spokesperson told Mongabay by email that ZSL’s report used data the company had published by the end of 2023. The spokesperson added that as of the end of 2024, the Michelin Group had verified that “98% of its natural rubber supply is deforestation-free”.

A spokesperson from the Italy-based tire manufacturer Pirelli, also named in ZSL’s analysis, told Mongabay by email that to ensure no-deforestation in their supply chain, the company is working toward 100% use of Forest Stewardship Council (FSC)-certified natural rubber in its European Plants by 2026.

Citing research from the Royal Botanic Garden Edinburgh, Ginger told Mongabay that rubber cultivation is estimated to account for more than 4 million hectares (about 10 million acres) of forest loss in Southeast Asia since 1993.

ZSL said in its statement that the report’s findings raise concerns about the rubber industry’s commitment to the EU Deforestation Regulation (EUDR). The EUDR requires that companies importing certain commodities into the EU must trace the origin of their suppliers and ensure they’re not sourcing from land deforested after Dec. 31, 2020. The law becomes mandatory for large companies by the end of 2025.

Yet, of the 24 companies that source rubber from industrial plantations, none disclosed the location of their suppliers, suggesting the industry is hesitant to comply with the EUDR, ZSL said.

Ginger said that large rubber companies face the challenge of having complex supply chains; 85% of production often comes from smallholder farms.

While the problem is tricky, Ginger said downstream buyers can work closely with processing facilities, and adopt emerging technologies to trace supply chains.

Michelin’s spokesperson said the group has been working since 2023 “to ensure that all the natural rubber used in its tires and products are respecting EUDR definitions & requirements”. This includes “geolocalising its supply chain at the farm level” by satellite and geospatial analysis tools to ensure absence of deforestation in millions of smallholder farms.

Banner image of a rubber plantation in Kerala, India, by Vis M via Wikimedia Commons (CC0 1.0 Public domain).