Environmental Protection

Water is an indispensable component of the Mitsui Chemicals Group’s various chemical product manufacturing processes. For example, water is used in manufacturing processes that include heating, cooling, and washing as well as for equipment that removes harmful chemical substances produced during these processes and discharges effluent.
Formulating its basic philosophy on water resources, the Mitsui Chemicals Group works to manage efficient water usage and water preservation. Under our Climate Change Policy, we also address climate-induced water hazards, such as floods, droughts, and changes in water pollution, specifically at our production sites, while promoting the risk management and effective use of water resources at these locations. In addition, through our Sustainable Procurement Guidelines, we ask suppliers to manage wastewater and use water efficiently, thereby contributing to water resource conservation across the entire supply chain.

The Mitsui Chemicals Group positions the conservation of the water environment as one of its environmental priorities and has established target values based on standards specified by laws and regulations. We continuously monitor emissions of water quality contaminants, such as chemical oxygen demand (COD), nitrogen, and phosphorus, against these standards to help preserve the water environment. As a result, emissions of each water quality contaminant are maintained at levels well below the target values.

At domestic production sites with high water usage, wastewater discharged from individual plants is collected and subjected to preliminary treatment, including neutralization, oil separation, and removal of solids. The wastewater is then appropriately managed through an activated sludge process that utilizes microorganisms to further reduce organic substances.

However, some wastewater cannot be adequately treated by the activated sludge process alone, as it contains organic substances that are difficult for microorganisms to decompose or substances that inhibit microbial activity. Therefore, depending on the characteristics of the wastewater, advanced treatment methods such as ozone treatment, combustion treatment, and anammox treatment are applied before conventional wastewater treatment is conducted, thereby helping to reduce impacts on the water environment.*

The Mitsui Chemicals Group conducts water risk assessments for its production sites from the present up to the year 2050. As assessment tools, we mainly use the AQUEDUCT Water Risk Atlas from the World Resources Institute (WRI) and the Water Risk Filter from the World Wide Fund for Nature (WWF). First, we identify potential areas with water stress using AQUEDUCT, and then assess and determine water-stressed areas using the Water Risk Filter, which offers a different perspective.

As a result, the FY2025 assessment identified two sites, one in India and one in the United States, as water-stressed areas. However, based on external assessments incorporating local information, including the water intensity of products manufactured at the sites, water consumption, and regulatory information, we confirmed that the risk associated with water stress is not high at either the India or U.S. site. Going forward, we will manage water resources with consideration for regional characteristics and, where necessary, implement measures such as reducing water withdrawal and increasing the use of recycled water. We will next conduct a detailed assessment of the site in the United States.

In addition, water risk assessments of production sites using these tools are conducted annually, and similar assessments are also carried out when new plants commence operations. Given the increasing demand for assessments from a double materiality perspective in the environmental field, we will restructure our comprehensive water risk assessment methods to include natural capital and biodiversity. Including biodiversity risk as a part of water risks, we use IBAT to gather data and investigate biodiversity risk based on the following evaluation items: protected areas, priority conservation areas, endangered species, and endangered freshwater species at our production sites.

In support of the TCFD recommendations, we are conducting assessments on the physical risks to our production sites (such as floods), based on IPCC RCP 4.5 and RCP 8.5. In identifying sites to be assessed, 68 sites in 10 areas that rank high in importance (Japan, China, Korea, Taiwan, Southeast Asia, India, United States, Europe, Brazil and Mexico) have been selected for analysis and assessment for the risk of river floods and coastal floods (storm surges). The risk of floods tends to be high in East Asia including Japan and China, and Southeast Asia, and the number of disasters is expected to increase in many areas.

Also, as part of the risk impact assessments, we estimated the amount of reduction in asset value and the amount of damage due to business interruption caused by floods from 2020 to 2080, utilizing a particular assessment model. The assessment results suggested that in 2030 and onward, our domestic and overseas sites will be subjected to a greater risk impact from river floods. In conjunction with the further development of the physical risk assessment in the recommendations of the TCFD, we plan to further expand the number of production sites subject to impact assessment, determine whether actions need to be taken based on the impact assessment results, and reflect the necessary actions in our business strategy.