To help prevent leaf disease, Hankook implemented a project in Indonesia in 2022 to provide formic acid to farmers "to improve the environment of rubber tree plantations," Kim said.
"Acid is used as a coagulant to solidify latex collected from rubber trees. Since formic acid is less harmful than sulfuric acid, we have attempted to protect the growth of rubber trees through this support program," he said.
He added, however, that one of the most significant causes of leaf disease is indiscriminate tapping.
"If latex is collected continuously without giving enough time for the rubber trees to recover, the resilience of the rubber tree will inevitably decrease," he said. "Therefore, we continue to require NR processors to guide NR plantation farmers on collecting latex while keeping rubber trees resilient."
Like Michelin, Pirelli recognizes the value in seeking an alternative to hevea NR, but not moreso than supporting hevea NR production itself.
While the company made its first guayule-based UHP tire in 2016, it said it "does not currently feel these alternative materials are scalable due to volume issues."
The Italian tire maker also echoed Hankook's sentiment that while synthetics are useful in tires, they simply do not match their bio-based counterpart.
"Natural rubber is a key component of tires and other goods, and generally cannot be substituted with synthetic alternatives," Maureen Kline, Pirelli North America's vice president of Sustainability and Public Affairs, told Rubber News in an email.
"The industry needs to be sure of the supply of natural rubber, be prepared for price fluctuations, and ensure that we are good stewards, responsible for the impacts of our product," she added. "All of these things point to the need to map and understand supply chains and to engage with the value chain to promote a system that is fair, thriving and sustainable over the long term."
Pirelli has several programs to support these initiatives, including its own natural rubber policy, implementation manual and roadmaps, involving all natural rubber suppliers.
The company also has several partnerships with producers and communities, such as its Kirana Megatara project, which enhances training of smallholders, and the Hutan Harapan project, which raises awareness to protect forest biodiversity and improve the lives of the local people.
"In general, Pirelli is committed to improving our environmental and social impacts," Kline said. "Today, we have the leverage to change the way we source natural rubber, especially if we engage with the whole value chain and the entire industry."
Most recently, Pirelli acquired Brazil's largest independent NR producer, Hevea-Tec, which gives the tire maker "direct control" over its Brazilian NR supply chain, "and thus a greater ability to map the supply chain and implement engagement with smallholders and environmental and social protections."
"We must ensure that natural rubber is not contributing to deforestation, which is a key factor in climate change and biodiversity loss," Kline said. "And we must contribute to the sustainability of natural rubber business in the long term, considering that the global demand of rubber is expected to grow in the future."