Mitsui Chemicals, Lawson Break New Ground in Convenience Store Industry With "Bio & Circular" Initiative

Mitsui Chemicals, Inc. (Tokyo: 4183; President ＆ CEO: HASHIMOTO Osamu) announced today that the Prasus™ line of bio-based and chemically recycled polyethylene produced and sold by Prime Polymer Co., Ltd. (Chuo-ku, Tokyo; President ＆ CEO: YOSHIZUMI Fumio), a Mitsui Chemicals Group company, has been adopted for plastic bags offered at Natural Lawson stores operated by Lawson, Inc. (Tokyo: 2651; President ＆ CEO: TAKEMASU Sadanobu).

Starting from January 2026, Lawson will roll out bags made with Prasus™, which incorporates both bio-based polyethylene and recycled polyethylene allocated under the mass balance approach, as their sole main material. The rollout will begin with certain stores, with plans to eventually bring these bags to all Natural Lawson stores.

Plastics are linked to two key environmental issues: global warming and plastic waste. The Earth's temperature is predicted to increase by 5.7°C by the year 2100^*1, and Japan alone generates as much as 7.69 million tons of plastic waste per year^*2.

While Japan has a high recycling rate for plastic waste – 89 percent – thermal recycling accounts for 64 percent of this figure. Consequently, while this plastic waste is used as an effective source of heat and fuel, the fact that it is incinerated rather than reused as a material, which leads to CO₂ emissions^*3.

Out of plastic containers and packaging collected separately in line with the Containers and Packaging Recycling Act, approximately 45 percent is recycled through conventional methods^*4. In other words, while about half of this plastic waste is recycled into new materials, the other half is put toward means such as thermal recycling (not to be used as resource for recycled plastic), resulting in CO₂ emissions. This highlights the fact that a shift toward bioplastics – rather than relying entirely on recycling – will be essential to avoid increasing CO₂ in the atmosphere.

Lawson and Mitsui Chemicals have collaborated to develop these new plastic bags as part of a “Bio & Circular” initiative to highlight and address some of the issues surrounding plastics. Made with a mixture of bio-based and chemically recycled polyethylene as their sole main material, these bags will help to reduce the consumption of new fossil resources, increase the recycling rate via the reuse of plastic waste as a resource, and cut CO₂ emissions – the key cause of global warming – by 36 tons per year^*5.

Both Lawson and Mitsui Chemicals are committed to leveraging biomass and recycling approaches alike in the effort to reduce environmental impact and move toward a regenerative future.

The Ministry of the Environment’s Roadmap for Bioplastics Introduction defines the mass balance approach 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.”

The physical properties of plastics and chemical products made under the mass balance method do not differ whatsoever from their fossil-derived counterparts. The mass balance method also allows for the use of biomass and recycled feedstocks in materials where it has traditionally been difficult. As a result, the mass balance method is an important means of increasing society’s adoption of biomass and recycled resources and realizing a carbon-neutral and a circular-economy society.