Mitsui Chemicals has secured a significant new application for its bio-based plastics, with the materials now being used in transformer components manufactured by Toshiba Industrial Products and Systems.

 

This, as companies across Japan accelerate efforts to reduce carbon emissions throughout industrial supply chains.

 

The adoption marks another step in Mitsui Chemicals’ expansion of its BePLAYER portfolio of bio-based hydrocarbon derivatives, including biomass chemicals and plastics, designed to support the transition toward a low-carbon economy.

 

The company’s biomass plastics, produced using the mass balance approach, are now being incorporated into various plastic parts used in molded transformers compliant with Japan’s 2026 Top Runner energy-efficiency standards, as well as in coils for extra-high-voltage molded transformers manufactured and sold by Toshiba Industrial Products and Systems. 

 

Mitsui Chemicals is supplying the raw materials that support the initiative across the value chain.

 

The move aligns with Toshiba Group’s Environmental Future Vision 2050 and reflects growing industry efforts to achieve carbon neutrality while meeting increasingly stringent energy-efficiency requirements. 

 

The transformers not only comply with the third phase of Japan’s Top Runner standards, which took effect in April 2026, but also integrate biomass-derived materials into products traditionally reliant on fossil-based plastics.

 

Transformers demand exceptional levels of durability, safety and operational efficiency, making material selection critical. Mitsui Chemicals said biomass plastics produced through the mass balance approach deliver the same physical performance as conventional petroleum-derived plastics while reducing reliance on fossil resources.

 

Under the Ministry of the Environment’s Roadmap for Bioplastics Introduction, the mass balance approach is defined as: “A method in which, during the process of turning raw materials into final products and the distribution process (chain of custody), raw materials with certain properties (e.g., bio-based raw materials) are mixed with raw materials that do not have the properties (e.g., fossil-based raw materials); thus, the properties are assigned to a portion of the product according to the amount of input of the raw materials with those properties.”

 

Because plastics and chemical products produced under the mass balance system are physically identical to fossil-derived alternatives, the approach is increasingly viewed as a practical pathway for expanding biomass use in sectors where direct substitution has historically been difficult.

 

Mitsui Chemicals said that, as of June 2025, approximately 50 product groups across the company had already transitioned to biomass resources using the mass balance method. 

 

The company also sees the approach as a key enabler of chemical recycling initiatives that support the development of a circular economy, providing recycled and biomass-based plastics and chemicals without compromising product performance.

 

As manufacturers face mounting pressure to decarbonize operations while maintaining product quality and reliability, the adoption of mass balance-based biomass plastics in critical power infrastructure could signal broader industry acceptance of the technology.