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Environmental Management

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Environmental Management

Purpose of activities Activities during fiscal 2023 Self-
Targets/plans for activities from fiscal 2024 onwards
  • Complying with environmental legislation
  • Continuous improvement of environmental load
  • Strengthen efforts to observe environmental legislation
  • Step up education on environmental legislation
  • Strengthen efforts to comply environmental legislation
  • Step up education on environmental legislation

Self-assessment grades A: Target achieved B: Target mostly achieved C: Target not achieved


Environment Policy

This “Environmental Policy of the Mitsubishi Materials Group” was established based on the Sustainability Policy and is considered to be the foundation for the business activities of the Mitsubishi Materials Group.

Promote Recycling and Provide Environmentally Friendly Products
We leverage our advanced recycling technologies to promote recycling of waste. At the same time, we provide environmentally friendly materials and products across our business activities starting from raw material procurement to the development, production, distribution, consumption, disposal and recycling of raw materials and products.
Advance Decarbonization
We work towards the decarbonization of our business activities by reducing energy consumption. We will also tap into geothermal and other renewable energy sources to decarbonize our entire value chain.
Respect Biodiversity
We engage in business activities that take ecosystems into account throughout our value chain, including the development of natural resources.
Effectively Use and Conserve Water Resources
We work to reduce water consumption through circular water management and reuse of cooling water, cleaning water and all other water used across our business activities.
Sustainably Manage Company-Owned Forests
We make effective use of timber and other forest resources as well as ensure appropriate management of company-owned forests that contribute to decarbonization, biodiversity and water conservation and recreational activities of the local communities.
Encourage Environmental Education and Harmonious Coexistence with Society
We strive to reduce the environmental impact from our business activities and prevent pollution by educating all our employees on relevant laws, regulations, and agreements on an on-going basis. We communicate proactively with our stakeholders and engage in environmental conservation initiatives.

(Last revised date: December 1, 2021)


Promotion System

We have established the Environmental Management Panel to be a dedicated subcommittee under the SCQ Promotion Office that formulates and implements Group-wide environmental measures. We appoint environmental management supervisors for each business division and manufacturing site. They work to prevent pollution and ensure compliance with environmental laws and regulations by collaborating closely with the Head Office environmental management department.

Environmental Management System

Environmental Management System


Environmental Management Activities

Environmental Training

We operate environmental management systems under the ISO 14001 standard and other environmental management systems at our sites. Under those systems, we engage in continuous activities to ensure compliance with laws and regulations and improve our environmental performance. We have worked to develop and implement environmental training programs and legal checking systems to cultivate managers who possess knowledge of environmental technologies, laws and regulations.
In particular, the Group regards waste management as a key business process and promotes the use of recycled raw materials, such as in our metal smelting and refining business. We appoint staff who are responsible for waste management and those in charge of practical operations at each facility. We provide training on laws and regulations and apply strict operating rules in our efforts to ensure appropriate waste management and compliance with relevant laws and regulations. We provide education for staff responsible for waste management with the aim of understanding waste risks and the roles required by introducing the latest case studies on waste management. For staff in charge of practical operations, we organize seminars for understanding the specific regulations of the Waste Management and Public Cleansing Act.                          

Environmental training achievement in Fiscal 2023

Waste management training Managers 16
Operational personnel 121

Sharing Information to Address Environmental Issues

To handle the environmental issues that arise at our sites, we have established an office providing the consultation services of staff specialized in environmental issues, at our Head Office. This office provides detailed support, ensures that useful information is shared between the Head Office and other sites, and responds to environmental issues.
We hold an annual Meeting of Administrative Managers Responsible for Environmental Management for management-level staff at our facilities. At these meetings, we share information about environmental measures and issues. In addition, we give annual site tours for environmental management supervisors. These tours are opportunities to learn methods of operating onsite related to environmental management and initiatives for preventing environmental accidents, and to exchange information with supervisors from other sites.


Compliance with Environmental Laws and Regulations

We keep all our sites up to date on changes in legislation applied to the Mitsubishi Materials Group by providing information via intranet or email. In the event of major revisions or revisions requiring measures such as equipment upgrades, we hold explanatory meetings to share information on the requisite measures and ensure that all our sites are prepared to take appropriate action.
Current laws and regulations are checked periodically at each site. In addition, the Internal Audit Department checks the status of compliance with environmental laws and regulations, how chemical substances are handled, how equipment is managed and so on. When a noncompliance is discovered we correct it promptly and share information about it with related sites as part of our efforts to improve the level of management in the overall Group.
In the event of installation of new facilities, facility upgrades/changes, or any other projects involving new operations above a certain scale, individual sites as well as relevant Head Office divisions determine what notifications they are required to submit. In addition, to support specialized legal knowledge that is needed at sites, we built a web system and began operating it in April 2021. When a name or the specifications of a facility are entered in this system, it automatically judges whether a notification or a permit application needs to be submitted.

Status of Compliance with Environmental Laws and Regulations

With regard to our compliance with environment-related laws and regulations in fiscal 2023, including water pollution, air pollution and waste disposal, we were not subject to any adverse dispositions (revoked permits, orders to cease operations, orders to stop use of equipment, fines, etc.) by regulatory authorities.
We received 5 complaints regarding odors and waste. For all of these we promptly investigated the causes and implemented the necessary countermeasures.


Addressing Environmental Risks

In accordance with its Environmental Policy, the Mitsubishi Materials Group identifies environmental risks it faces and takes measures to prevent such risks from materializing.
Pollution of air, bodies of water, soil or groundwater by hazardous substance leaks, or inadequate treatment of industrial waste could have a detrimental impact on the environment, as well as a serious impact on our business activities as a group. We carry out risk assessments in line with the nature of our business activities, the substances that we handle, and the locations of individual sites, and take action as necessary. In addition to preventing inadequate waste treatment at our own departments, we take steps to ensure that we do not overlook inadequate treatment by contractors by taking measures including on-site confirmation.
At the closed mines (non-ferrous metal mines) we own, in order to prevent mining-induced pollution, we continue to maintain tailings dams, mining tunnels and mining water conduit, and to appropriately process acid wastewater containing heavy metals generated from these locations. Biodiversity is also an important environmental risk for us. At the mines from which we procure raw materials (such as ores), we have established environmental and social standards, including standards for the conservation of biodiversity, and we confirm our compliance with these standards. In addition, we manage the company-owned forests in Japan to ensure a high level of ecosystem services from them. They fulfill a certain standard that has been assured by our acquisition of a forest certification.
To reduce climate change risks, we take multiple approaches for the conservation of energy and the reduction of CO2 emissions. We also study CO2 capture and use, and generate renewable energy. Regarding the risk that a shortage of freshwater resources could impact our business activities, we conduct risk assessments for our major facilities in Japan and overseas and take measures including the effective utilization of seawater, water conservation through the improvement of the efficiency of the production process, water recycling, and ensuring that wastewater is treated and purified.


Environmental Accounting

In fiscal 2023, we invested approximately 13.1 billion yen in areas including construction at the Tohoku Power Service Station of the Komatagawa New Power Plant (hydroelectric power plant) certified as a renewable energy power generation facility, and the renewal of equipment at copper smelting and refining plants, with the goal of preventing air pollution and water pollution. Costs associated with environmental preservation came to around 6.4 billion yen, including environmental measures, and maintenance and management of equipment to prevent pollution.

Spending on Environmental Preservation in FY2023[Millions of yen]

Category Investment Amount Expense Amount
Business area costs Business area costs 13,019 6,012
Pollution prevention costs 1,493 2,884
Global environmental conservation costs 11,495 298
Resource recycling costs 31 2,830
Upstream/downstream costs 0 0
Administration costs 57 231
R&D costs 25 53
Social activity costs 0 0
Environmental remediation costs 5 104
Total 13,106 6,400
  • Calculations of environmental costs are based on the 2005 version of the Environmental Accounting Guidelines published by the Ministry of the Environment.
  • Figures refer to Mitsubishi Materials on a non-consolidated basis.


Overall Environmental Impact


Among the following disclosure items, energy input includes data from sites belonging to the polycrystalline silicon business and salt manufacturing business.

Total Energy Input

Total energy input (non-consolidated) in fiscal 2023 decreased by 5% (0.5 petajoules: crude oil equivalent of 13 thousand kiloliters) in comparison with fiscal 2023. This was partly due to a decrease in production at some plants, but also because of energy-saving activities such as the electrification of facilities and the introduction of high-efficiency equipment.

Total Energy Input


* 1PJ=1015J=1,000TJ

Raw Material Input

To contribute to the establishment of a material-cycle society, we are actively engaged in the recycling of waste and by-products, and promote the use of recycled raw materials such as waste and by-products. Total raw material input for the Company on a non-consolidated basis for fiscal 2023 declined 93% compared with fiscal 2022 to 1.3 million tons because the cement business was removed as a reporting entity from fiscal 2023. As a percentage of total raw material input, waste products and byproducts accounted for 13.4%.

Raw Material Input


* Natural resources include limestone procured from Group mines up to fiscal 2022.

Water Intake

The vast majority of our water intake is seawater used as cooling water at our copper plants.
On a non-consolidated basis, the Company’s total water intake in fiscal 2023 declined 77% compared with fiscal 2022 to 94.7 million m3 because the cement business was removed as a reporting entity from fiscal 2023. Only 11.4 million m3 (approximately 11%) of the total water intake was fresh water.

Water Intake (Excluding Seawater)


* Excluding fresh water used in hydroelectric power generation
* Excluding seawater used for cooling

Emissions into the Air and Bodies of Water

We monitor the amounts of sulfur oxides (SOx), nitrogen oxides (NOx) and dust contained in waste gases from facilities, as well as attributes such as BOD (biochemical oxygen demand), COD (chemical oxygen demand) and nitrogen content in wastewater. On a non-consolidated basis, the volume of nitrogen oxides (NOx) emitted into the air by the Company in fiscal 2023 declined 98% to 220 tons, dust declined 89% to 15 tons compared with fiscal 2022 because the cement business was removed as a reporting entity from fiscal 2023.

Emissions into the Air


Emissions into Bodies of Water


Water Discharged

On a non-consolidated basis, the volume of water discharged (excluding water drained into the sea) by the Company in fiscal 2023 declined 14% to 9.5 million m3 compared with fiscal 2022 because the cement business was removed as a reporting entity from fiscal 2023. Water drained into the sea by the Company (non-consolidated) was 85.3 million m3, and the vast majority was seawater that had been used as cooling water.

Water Discharged (Excluding Water Drained into the Sea)


* Excluding water drained into the sea

Chemicals Released or Transferred

The Company’s non-consolidated emissions in fiscal 2023 declined 48% compared with fiscal 2022 to 41 tons due to the cement business being removed as a reporting entity and the cessation of use of a large volume of chemical substances that were being used at one site from fiscal 2023. The transferred amount was 37 tons, a 12% decrease from fiscal 2022.

Chemicals Released or Transferred


Volume of Industrial Waste

The volume of industrial waste from the Company (non-consolidated) in fiscal 2023 declined by 19% compared with fiscal 2022 to 11.3 thousand tons because the cement business was removed as a reporting entity from fiscal 2022. The volume of waste sent to landfills by the Company (non-consolidated) in fiscal 2023 was approximately 4.7 thousand tons, which was 18% decreased from fiscal 2022.
The total volume of waste for the Group as a whole, including Mitsubishi Materials, came to approximately 45 thousand tons, of which around 50% was recycled.

Volume of Industrial Waste




Preventing Environmental Pollution

Preventing Air Pollution

The Group uses manufacturing processes that emit air pollutants such as dust and sulfur oxides (SOx) as a result of burning fuel, etc. In particular, emissions from our copper smelting and refining plants account for the majority of those emissions. Each site is working to suppress emissions of air pollutants by stabilizing and increasing the efficiency of operations that generate emissions, and by installing advanced waste gas treatment equipment and maintaining appropriate performance.


Preventing Water Pollution

To prevent water pollution, at all of our sites we appropriately treat effluent and impose wastewater management standards that are even stricter than those required by law or municipal ordinance. In addition, to ensure we are ready to deal with leaks of chemical substances or oil spills, we take measures such as installing dikes and inspecting equipment on a daily basis. We also conduct regular training aimed at preventing the spread of substances in the event of a leak.


Chemical Substance Management

The Group’s manufacturing plants handle a diverse range of chemical substances. Each site is implementing measures to reduce environmental risks, such as reducing the use of hazardous chemical substances, preventing their leakage into the environment, and reducing emissions. Specific initiatives include the review of processes according to the characteristics of each chemical substance, the installation of new equipment, as well as the switch to less hazardous alternative substances.


Waste Management

To contribute to building a resource-recycling society, we take comprehensive measures to reduce waste discharge and recycle resources from discharged waste. We also engage in recycling operations.


Managing Closed Mines

Purpose of activities Activities during fiscal 2023 Self-
Targets/plans for activities from fiscal 2024 onwards
  • Managing closed mines
  • Ongoing training of engineers managing closed mines
  • Upgrading aging facilities (continued)
  • Tailings dam reinforcement work (continued)
  • Ongoing training of engineers managing closed mines
  • Upgrading aging facilities (continued)
  • Tailings dam reinforcement work (continued)

Self-assessment grades A: Target achieved B: Target mostly achieved C: Target not achieved

Managing Closed Mines

We are a company with its origins in the mining industry. The Mitsubishi Materials Group owns a wide range of mines around Japan, including limestone, coal and nonferrous metal mines, such as copper, lead and zinc mines. Operations at all of our non-ferrous metal mines have now been suspended or discontinued. Currently, we are managing 21 closed mines across 15 locations. We have continued to implement the following controls and management programs for our closed mines on a long-term basis, pursuant to Article 5 of our Code of Conduct, which states, “[Environmental Management] We will work to manage our environmental impact and promote decarbonization, make efficient use of natural resources, and accelerate recycling.”

  • Appropriate treatment of the heavy metal-containing wastewater (acid mine drainage) released from former mining sites
  • Management of tailings dams (sites used to store rubble from mining minerals, slag and sediment from mine drainage treatment).
  • Inspection and maintenance of excavated mine underground spaces, drifts and channels for conducting mine drainage
  • Safety measures to prevent unauthorized entry at disused mine mouths and subsidence sites

We continue to preserve and maintain sections of mine drift in some closed mines as cultural heritage sites or tourist facilities to exhibit their former conditions and preserve historical mining technologies for future generations.

Closed Mitsubishi Materials (non-ferrous) Mines

Abandoned Mitsubishi Materials (non-ferrous) Mines

Overview of Acid Mine Drainage Treatment at Closed Mines

Broadly speaking, acid mine drainage can be generated in two ways. There is the acidic water in the pits (mine water) containing heavy metals, generated through contact between oxidized minerals and rainwater and groundwater, which can fill the underground pits and mining cavities formed in mineralized belts due to mining operations. Then there is the permeated water (wastewater) generated when small amounts of heavy metals, which are contained in slag and other substances in the tailings dams, come into contact with rainwater and surface water. The acid mine drainage goes to processing plants, where it undergoes neutralization and the removal of heavy metals. The water is then discharged into rivers at water quality levels that fall within wastewater standards.

Overview of acid mine drainage treatment at abandoned mines

Major Management Tasks for Closed Mines

The Group controls acid mine drainage treatment, tailings dams, mine drifts and entrance drifts. Acid mine drainage treatment involves the appropriate processing. Tailings dam control involves preventing stored slag and sediment from leaking out in case of dam body collapse. Mine drift and entrance drift control involves inspections to maintain waterways for acid mine drainage and sealing entrances to prevent injuries due to third-party trespassing in mine drifts and mine drift collapse. Of these measures, acid mine drainage control is carried out around the clock every day of the year.

Acid mine drainage treatment facilities (Yatani Mine)Acid mine drainage treatment facilities (Yatani Mine)

Example of tailings dam management (Osarizawa Mine)Example of tailings dam management (Osarizawa Mine)

Digitalization of Management Tasks for Closed Mines

We are pushing forward with the digitalization of management tasks for closed mines to improve the management and efficiency of the tasks.

  • Operational data is collected automatically and centrally managed and utilized as digital data. The use of this digital data enables the remote management of operations at acid mine drainage treatment facilities and other locations.
  • We have improved management by creating a system for the early detection of abnormalities, including the visualization of operational data (such as the creation of graphs showing change over time) and remote alarms that are triggered when an abnormality is detected.
  • We use smart devices to inspect and maintain records of acid mine drainage treatment facilities and tailings dams, digitizing the inspection results for centralized management. This ensures the efficiency of the tasks by, for example, automatically creating reports.

Visualization of operational data (displaying data trends)Visualization of operational data (displaying data trends)

Recording inspection results using smartphone (digitalization of inspection data)Recording inspection results using smartphone (digitalization of inspection data)

Facility Upgrading and Environmental Countermeasures for Closed Mines

Since 2015, our Group has been implementing responses to deteriorating natural disasters and other risks by conducting protective construction to guard against contamination, as well as reinforcing tailing dams to prevent uncontrolled release of slag and sediment in anticipation of a major earthquake, reducing wastewater at the source, strengthening the capacity of acid mine drainage treatment facilities, and upgrading aging facilities. We recorded an environmental countermeasure reserve for work expenses from fiscal 2016 to fiscal 2019, and in fiscal 2023 we appropriated some additional funds to cover expenses for the repair and toughening of locations damaged due to torrential rains.

Tailings Dam Reinforcement

Drawing on lessons learned from the leakage of slag and sediment at tailings dams managed by other companies during the Great East Japan Earthquake, in November 2012, the Ministry of Economy, Trade, and Industry revised its technical guidelines on aseismic performance. Based on this, we evaluated the stability of the tailings dams managed by the Group, which revealed that measures needed to be implemented at 10 locations. Thus, we started construction work to design and implement stability measures at the locations in fiscal 2016, and have completed these measures at eight of the locations.

Reinforcement work by soil stabilization at the Yatani Mine Tailings Dam (after completion)Reinforcement work by soil stabilization at the Yatani Mine Tailings Dam (completion)

Wastewater Reduction at the Source

The operational burdens and risks associated with acid mine drainage treatment due to environmental changes (large-scale typhoons and guerrilla rainstorms) in recent years have increased. To ease these burdens and mitigate the risks, we are proceeding with source countermeasure construction, the strengthening of acid mine drainage treatment facility capacity and updating aging equipment. One way of the source countermeasures is to cover exposed surfaces of mineralized belts on a large scale, such as by using the latest technology (which enables greening that was previously difficult due to acidic rock conditions). This prevents rainwater from coming into direct contact with the mineralized belts, which is expected to reduce the amount of water to be processed as well as the burden of contamination.

before work

after workContamination containment work(Komagi Mine) (Top: before work, Bottom: after work)

Upgraded pit wastewater treatment facility (Osarizawa Mine)Upgraded pit wastewater treatment facility (Osarizawa Mine)

Human Resources Development

All the Group’s non-ferrous metal mines are closed and some time has passed since the mines were closed down. As such, we have seen a decrease in relevant human resources as engineers with skills in non-ferrous metal mine management have either reached advanced age or retired. In order to continue to sustainably manage closed mines, we are continually providing opportunities to train young engineers with little mining experience, and setting up a variety of educational programs for engineers (including programs for acquiring skills for the management of closed mines and for obtaining relevant qualifications), including the use of web training and on-demand instruction. In this way, we strive to transfer mine management skills.

Engineer training (mine tunnel management)Engineer training (mine tunnel management)

Engineer training (basic training)Engineer training (basic training)

Joint Industry-academic Activities

We have opened an endowed laboratory in the field of resources environment and remediation at Hokkaido University, and since fiscal 2018, we have continued to engage in a variety of education and research activities related to the protection of the mine environment. In coordination with the endowed course described above, we engage in a variety of R&D activities to repair and protect mine environments with the help of Hokkaido University as well as other universities and research institutions. We have widely publicized the achievements of these R&D efforts by presenting them in research papers, at symposiums and at other events.

  • Greening of former mining sites (University of Tsukuba, Hokkaido University): We are researching the heavy-metal resistance that endophytic fungi can provide to plants in former mining sites, as well as researching and investigating greening by native plants, in our efforts to facilitate the greening of former mining sites, where it has been difficult for plants to take root.
  • Examination of a method to evaluate ecological effects (National Institute of Advanced Industrial Science and Technology): We are examining a method of evaluating ecological effects of inflow of mine drainage on rivers from the viewpoint of effects on aquatic organisms by using field surveys.
  • Development of a remote monitoring technology (National Institute of Advanced Industrial Science and Technology): We are developing a super power-saving remote monitoring system with radio wave directivity, a technology that will enable the collection of management data from remote locations in mining areas without a power grid or communications network.
  • Other (Hokkaido University): To improve issues with the operation and management of acid mine drainage treatment, we have begun a new study to evaluate the risks of the leaching of heavy metals from neutralizing precipitate and understand the sedimentation mechanisms of manganese oxides under low concentration conditions.

A plant tour given to students from an endowed laboratory (site tour)A plant tour given to students from an endowed laboratory (site tour)

A greening survey at a former mining siteA greening survey at a former mining site

A river ecological survey (collection of benthos)A river ecological survey (collection of benthos)

Communication with Local Residents

To promote local residents’ knowledge of our measures for preventing mining-induced pollution at our closed mines, we proactively hold sessions to explain countermeasure work and offer facility tours. We also strive to take part in environmental conservation activities and contribute to local communities through tree-planting and the release of juvenile fish, as well as participation in and cosponsoring of local events and festivals. In addition, we accept inspection tours of our mining facilities by students and researchers from Japan and overseas. We thus offer our facilities as locations for research and development and skills training related to the prevention of mining-induced pollution.




Water-related Management

The vast majority (approx. 88%) of the water we consume at the Mitsubishi Materials Group is seawater used as cooling water. Consumption of fresh water (such as industrial water and groundwater) is comparatively low. However, because a shortage of fresh water may affect our business activities, securing the necessary quality and amount of water is essential for the business operation of the Group. One of the Group’s environmental policies is “Effectively Use and Conserve Water Resources,” and we are working to reduce the amount of water we use through its reuse, recycling and other efforts across every aspect of our business activities, including cooling water and cleaning water.
In addition, we have considered the seriousness of the water-related problems that have occurred frequently in recent years, such as typhoons and flooding, and the great impact of these problems. We manage the risks related to these problems accordingly. We implement measures for reducing water risks at individual facilities. To reduce our use of freshwater resources, we take action such as the effective use of seawater, water conservation through more efficient production processes, water recycling, and the thorough purification of wastewater. To secure water resources, we save water through measures including the recycling of water, the introduction of equipment with low water consumption, and the renovation of equipment to reduce water consumption. As measures against flooding, we take initiatives including the elevation of buildings, pumps, and electric equipment, the installation of drainage pumps, as well as the implementation of disaster drills assuming high water events. We also take measures to prevent abnormalities in the quality of the effluent from our facilities and to prevent water quality accidents. These measures include the management of effluent under our own standards that are stricter than laws and regulations, as well as the introduction of sensors that detect abnormal water quality and a system that stops water discharges automatically.

State of Water Risk Assessment Initiatives

To ascertain the state of water risks at the Group's manufacturing facilities (some of which include research institutes), we are utilizing the Aqueduct water risk assessment tool developed by the World Resources Institute (WRI) to conduct individual risk assessments for each facility, covering various water risks including those relating to securing water resources and those of incurring flood damage.
There were eight Group company locations rated as having high water stress, but sales related to these locations accounted for 7% of Group company sales. In fiscal 2023, water withdrawal was 99,585 thousand m3 and water consumption was 1,363 thousand m3. Additionally, in order to ensure that water risk assessments are in line with actual conditions at these facilities, we supplement the results of water risk assessments performed using Aqueduct by taking into account information including the history of any past water risks that have materialized at each facility (history of occurrences of flood, drought, and water supply quality deterioration, etc.) and water usage associated with business activities (amount of fresh water and groundwater used, emissions of pollutants contained in wastewater).
The results of these supplemented water risk assessments are used to produce visual representations of water risks for each facility, using radar charts displaying risk scores for each assessment item, and shared with each business location. Each business site registers items assessed as high risk as risk factors unique to that facility, and engages in risk management by formulating and implementing measures including the reduction of water risks.

Example Radar Chart Showing Water Risks for Each Facility


"Water quality risks" are assessed separately for both water supply and wastewater, from the viewpoints of impact on operations due to the deterioration of water supply quality and impact on the environment due to wastewater at business sites. "Regulatory and reputation risks" are also assessed for both water supply and wastewater, from the perspectives of toughness water supply and wastewater regulations and the reputation of the region.


MMC, MBS, DFF Inc., Trans-Asia Inc., ideaship Inc., KPMGあずさサステナビリティ

Biodiversity Conservation

Preserving the Natural Environment

Theme of activities Results of activities during fiscal 2023 Self-
Targets/plans for activities from fiscal 2024 onward
  • Contributing to local communities, society, and the global environment through sustainable management of company-owned forests
  • We received and passed periodic screenings to maintain forest certification from the Sustainable Green Ecosystem Council (SGEC). (Site inspections were conducted at Teine Forest and Bibai Forest.)
  • Maintain SGEC forest certification
  • We maintained forests appropriately based on our forest management plan, including cutting and thinning (133.56 ha), planting (11.19 ha) and weeding / clearing away underbrush (59.26 ha).
  • Promote environmental conservation of forests by maintaining forests appropriately based on our forest management plan
  • We tried to develop forests by making use of nature’s strengths, aiming for both environmental and economic achievements.
  • Pursue beautiful forests that are resistant to disasters and have high public interest functionality, through various effective forest development practices
  • We performed tree thinning with small-scale work channels at Teine Forest and Ikuno Forest, as a method for implementing disaster-resistant forest development.
  • The environmental impact of thinning is small, and a beautiful finish has been achieved through the application of horse logging (a method of timber gathering that makes use of horses).(Hayakita Forest)
  • We enhanced monitoring activities such as the introduction of a smartphone app to more accurately assess the state of the conservation of biodiversity, changes in ecosystem services (public functions) that occurred through forest maintenance, and the amount of forest growth, etc.
  • Consistently implement monitoring activities and establish quantitative evaluation methods for evaluations ecosystem services (public function) in collaboration with research institutions
  • We have conducted measurement tests of the amount of forest resources using remote sensing technologies including drones and satellite data, and achieved a certain level of precision.
  • Efficiently ascertain and organize forest data utilizing remote sensing, ICT and IoT technologies
  • We donated Christmas trees made with trees from company-owned forests and tree graduation certificates made using wood from company-owned forests to preschools in company-owned forest areas and held tree planting events for them.
  • Continue to contribute to local communities through services related to company-owned forests (initiatives such as the donation of Christmas trees)
  • We provided wood as a building material for elementary and junior high schools in Abira Town, Hokkaido, where our company-owned forest is located, as an initiative to effectively use the wood from company-owned forests.
  • Increase the value of company-owned forest by promoting utilization of high added-value wood from company-owned forests and contribute to economically sustainable forest management
  • We make company-owned forests available as sites for the nature experience activities of local NPO organizations, training for the purpose of popularizing the forestry industry, research / surveys by universities and other research institutions, and sports competitions, etc.
  • Promote the provision of company-owned forests as sites for recreational activities, education, research, and training

Self-assessment grades A: Target achieved B: Target mostly achieved C: Target not achieved


Preserving Biodiversity

The preservation of biodiversity is an element that forms the basis of our approach to business. We clarify this point both internally and externally by stating, “We will be more considerate of biodiversity and work to live in the harmony with nature”, in the Article 5 of our Code of Conduct. In addition, in our Environmental Policy we state, “We engage in business activities that take ecosystems into account throughout our value chain, including the development of natural resources.”
In our business activities, the impact on biodiversity is particularly notable at the overseas mines from which we procure raw materials. At the copper mines in which we have invested and are our important suppliers (Copper Mountain Mine in Canada, Escondida Mine in Chile, Los Pelambres Mine in Chile and Mantovelde in Chile), an Environmental Impact Assessment was appropriately conducted before the mining operations commenced and environmental monitoring has continued ever since. In ongoing copper mine development projects (at Zafranal in Peru and Namosi in Fiji), we are carrying out environmental baseline studies for Environmental Impact Assessment and collecting data for preserving diversity.

Copper Mountain is committed to biodiversity conservation management and reclamation, focusing on minimal disturbance and increasing areas that can be reclaimed prior to site closure. More specifically, Copper Mountain has developed strategies for achieving end land use and reclamation objectives, including improving physical stability, water quality and water-course protection, sediment retention and erosion control, soil salvage and storage, suitable revegetation, and the eradication of invasive species. These strategies, along with our plan to manage biodiversity conservation for vegetation, wildlife, water, and aquatic components, and a detailed monitoring plan for reclamation, are outlined in Copper Mountain’s Biodiversity Conservation Management Plan.
As an investor, we confirm in advance with operators of the mines that these initiatives will be taken, and encourage them to take such initiatives. In addition, when we procure materials from a mine in which we do not invest, we confirm that considerations are given to natural protected areas and biodiversity is preserved, in accordance with the CSR Procurement Standards of Metals Company.
We also take initiatives to preserve biodiversity at our manufacturing facilities by considering the characteristics of each site. For example, at Naoshima Smelter & Refinery (Naoshima Town, Kagawa County, Kagawa), we have been engaged in tree-planting activities at a rate of one hectare per year with the aim of promoting vegetation and restoring forests which were partially destroyed by forest fires in the past and where it is difficult for plant life to grow due to the dry soil conditions and low rainfall. Naoshima Smelter & Refinery also ensures thorough treatment of exhaust gas and effluent released from the facility under its own standards, which are stricter than government standards, in its efforts to protect the natural environment of Setouchi.

We own 14,000 hectares of forest across Japan and manage it by considering the habitats of the plants and animals that live there. We carry out wildlife monitoring and include rare species confirmed to be living in the areas on our red list. Our nine forests in Hokkaido have obtained certifications for sustainable forest management with consideration for biodiversity. We will continue to consider the contact points between our business activities and biodiversity, and take action to conserve biodiversity from a broad perspective.

Participation in the 30by30 Alliance for Biodiversity
- We Will Make Use of Our Company-Owned Forests to Contribute to Conservation of Biodiversity -

Mitsubishi Materials Corporation has been enrolled as a participating company in the 30by30 Alliance for Biodiversity ("Alliance") at the initiative of the Ministry of the Environment as of April 2022.
This Alliance is a coalition of the willing established for the achievement of the nature-positive global goal to halt and reverse biodiversity loss by 2030.
To accomplish this goal, Japan, with the aim of achieving the conservation and protection of at least 30% of the country's lands and waters by 2030 (30by30), has committed not only to expanding protected areas such as national parks, but also to designating as OECMs (other effective area-based conservation measures) areas other than protected areas, such as company forests, conducive to the conservation of biodiversity.
We aim to register the forests we own as “natural symbiosis sites” as part of an initiative led by the Ministry of the Environment to obtain “Other Effective area-based Conservation Measures” (OECM) certification.


Biodiversity Initiatives at Our Mine

Monitoring Water Quality at Copper Mines (Copper Mountain Mine)

We invest in Copper Mountain Mine, located in British Columbia, Canada, where we engage in corporate management with an emphasis on biodiversity.
Copper Mountain Mine (CMM) begin our mine planning process with a comprehensive progressive reclamation plan to safely transition from mining operations to closure. This plan includes planning for closure, allocating appropriate resources for reclamation, and involving stakeholders, including local First Nations, at the earliest stages of operations. At the CMM, they are working with First Nations to clarify end land use objectives, and to understand and disseminate information about the baseline conditions related to the social, economic, environmental, and cultural aspects of our operations and the desired recreational and traditional end land uses for the mine site.
CMM’s progressive reclamation begins at the mine planning stage and is continuously executed as a part of mine operations. This progressive reclamation process started at CMM in 2018. The 2018 reclamation areas were small-scale initial trials. This progressive reclamation program is based on 25 hectares of reclamation per year over the next 10 years.
In 2022, CMM completed reclamation monitoring on all the reclaimed areas around the site. This included documenting observations of the existing vegetation species and their overall health. CMM also tested the soils and vegetation for various nutrients to ensure a thorough understanding of the soil condition and plant health. In 2023, CMM plan to commence planting shrubs and trees on the Non-Economic Rock Storage Areas (NERSA) in the areas previously identified for reclamation.
Results of Reclamation Monitoring at Copper Mountain Mine are shown below.

Year Progressive Reclamation activity (ha)
2022 20.31
2021 23.97
2020 20.99
2019 7.47

In 2022, the following trees and shrubs were planted in the Wolfe Creek Realignment Area, a small creek neighboring the mine.

  • 976 trees planted
  • 7,500 shrubs planted
  • 2,500 willow and dogwood stakes planted

In addition, we continually monitor the quality of water in local rivers, in accordance with quality guidelines issued by the provincial government, and also carry out ongoing biodiversity surveys of the surrounding area in order to gauge the impact of our activities on the ecosystem, including birds, mammals, amphibians, aquatic organisms and their habitats.
In 2019 we launched the Fish Habitat Offsetting Plan (FHOP) to offset a portion of the aforementioned Wolfe Creek, and have continually engaged in environmental monitoring thereafter. The habitat for organisms in the offset stream was recognized as a good fish spawning and rearing environment for rainbow trout and other species, and in 2022 the Copper Mountain Mining Corporation received an award in the Metal Mine category from the British Columbia Technical and Research Committee on Reclamation in recognition of this achievement.

The FHOP siteThe FHOP site

A rainbow troutA rainbow trout

Environmental Impact Assessment as part of Copper and Gold Deposit Development Project

We are carrying out a basic environmental study geared towards conducting EIA* as part of a development project in Zafranal, in southern Peru. At the same time, we are studying and analyzing ways to minimize the potential impact on the environment by the development, and are looking into measures to secure new habitats for species of flora and fauna if there is a risk of any impact on the ecosystem.

* Environmental Impact Assessment

Exploration drillingExploration drilling

River water quality surveyRiver water quality survey

Environmental Impact Assessment on Construction of Power Plants

Environmental Impact Assessment for Launch of Operations of Appi Geothermal Plant

In 2015, we established Appi Geothermal Energy Corporation in conjunction with Mitsubishi Gas Chemical Company, Inc. to the west of Appi Highlands in Hachimantai City, Iwate. We were joined by Electric Power Development Co., Ltd. in 2018, and the three companies are promoting the project towards the launch of the operation. The project aims to begin operating a 14,900 kW geothermal power plant in 2024. Appi Geothermal Energy Corporation began procedures for an Environmental Impact Assessment in 2015, and studied, predicted, and assessed the impact of the construction of the Appi Geothermal Power Plant on the surrounding environment. The company received approval for the final environmental impact statement from the Minister of Economy, Trade and Industry in January 2018 and began construction of the plant in August 2019.

Voluntary Assessment of the New Komatagawa Hydroelectric Power Plant

We own a hydroelectric power plant immediately below the Moriyoshi Dam in the Komata River, a branch stream of the Ani River in the reservoirs along the Yoneshiro River in Kita-Akita City, Akita. In May 2019, we began construction on the New Komatagawa Hydroelectric Power Plant (rated output: 10,326 kW), a hydroelectric power plant that will use the discharged water which was used for power generation at the existing plant. When planning the construction of the new power plant, we undertook a voluntary environmental assessment to determine the impact on the surrounding environment. We are also creating a new plan to ensure that the flow rate of surplus from the new plant will be appropriate for the river to preserve the surrounding river environment. In addition, we will carry out eco-friendly construction work. We will use power supplied from the existing hydroelectric power plant, a renewable energy, for construction work on the headrace tunnel with TMB method. We will also engage in environmental initiatives including the recycling trees that were felled to construct the new power plant.

Biodiversity Conservation Activities of PT Smelting (Indonesia)

Activities for Protecting Rare Animals

To further develop its activities for environmental protection and biodiversity preservation, PT Smelting has been co-sponsoring a program for protecting rare animals by Taman Safari Indonesia since 2018.
In this program, endangered species designated by the International Union for Conservation of Nature (IUCN) are bred and released into the wild to ensure their sustainability. PT Smelting participates in a program to protect Javan hawk-eagles. The Javan hawk-eagle is the national bird of Indonesia because it has the same characteristics as Garuda, the divine bird in the national emblem of Indonesia (Garuda Pancasila). However, recently there is concern over the decrease in the population of this species due to the destruction of rainforests as well as poaching. Through this program, the company not only aims to breed Javan hawk-eagles as a national symbol but also to support the education of children as future leaders and biological research on the birds, thereby contributing to preserving biodiversity.

Javan hawk-eagleJavan hawk-eagle
Photo provided by Taman Safari Indonesia



Materials' Forests

Sustainable Management and Operation of Company-owned Forests

Basic Approach to Sustainable Forest Management

We currently own around 14,000ha of forestland in Japan, mainly in Hokkaido, making us one of the largest owners of forestland in the country. We previously began acquiring forests for the purpose of supplying wooden supports for our own mines and coal mining activities. However, due to the closure of our domestic mines and coal mining in general, our forests now fulfill different roles and are subject to different expectations.
We are managing the forests for the purpose of harnessing their ecosystem services in a high level. Those services include not only the production of lumber as a renewable resource but also the provision of public recreational spaces, the prevention of global warming through CO2 fixation, and the conservation of biodiversity.
Each of the company-owned forests vary by area in terms of location and environmental conditions, as do the functions they are hoped to fulfill. As such, we have adopted four categories (zoning) by which to divide the forests we manage: water and ecosystem conservation zones, health and cultural usage zones, selective natural forest cutting zones, and timber resource recycling zones. We specify what functions need to be improved and what management methods apply for each zone type. While thoroughly implementing this kind of meticulous forest management, we are pursuing beautiful forests that are rich in function, based on the slogan: “A "beautiful forest" that is needed by society by making the most of natural resources and maximizing their functions and utilization.”
By way of outside recognition for sustainable forest management initiatives such as these, on October 1, 2012, we obtained certification from the Sustainable Green Ecosystem Council (SGEC) at Hayakita Forest in Hokkaido. Since then, the SGEC has implemented certification standards outlining transitional procedures for mutual certification with the Programme for the Endorsement of Forest Certification (PEFC), an international forest certification scheme. With that in mind, we simultaneously obtained forest certification under the SGEC’s new standards for a total of nine forests in Hokkaido on September 1, 2015, including Hayakita Forest.


The Zoning of Company Forests and Management Policies

Zone Activity
Water and ecosystem conservation zones Maintain the natural forest by the water and convert it into a natural forest if artificial
Health and cultural usage zones Create a model forest and facilities for walking and other forms of forest recreation
Selective natural forest cutting zones Produce useful broad-leaved trees in a sustainable manner by felling trees in naturally regenerated forests within a range not exceeding their growth
Timber resource recycling zones Actively encourage tree-planting and thinning in the artificial forest cycle to contribute to decarbonization

Data on Company-owned Forests

31 locations nationwide
Total area Approx. 14,000ha
SGEC certified area 11,431ha
  • 9 forests in Hokkaido
Natural forest Approx. 7,000ha
Artificial forest Approx. 7,000ha

Hayakita ForestHayakita Forest
The forest is laid out in a mosaic pattern, based on appropriate zoning between naturally regenerated forest (a forest made up of trees that have grown naturally), which has been conserved as a water and ecosystem conservation zone, and afforestation areas (trees grown from seedlings planted manually), planted with Japanese larch to be used as recycled resources for efficient lumber production.

The Value of Company-Owned Forests: Contributing to a recycling-oriented society, Contributing to a low-carbon society, Contributing to the local community, Conserving Biodiversity

Distribution and Scale of Company-owned Forests[photo]


1. Contributing to a Recycling-Oriented Society
–Supplying Society with Sustainable Timber Resources–

Timber is an outstanding sustainable resource. We produce approximately 10,000 m³ of timber every year, mainly in timber resource recycling zones and selective natural forest cutting zones, and supply the timber to society as raw materials and fuels for a variety of products, from building materials to woody biomass fuels. We thus contribute to building a recycling-oriented society. To enable a sustainable lumber supply, we appropriately maintain and regenerate forest resources by following the management policy formulated for each zone. In timber resource recycling zones where we manage artificial forests, we maintain the cycle of thinning and planting trees, thereby ensuring a sustainable, stable supply of lumber from needle-leaved trees such as cedar and Japanese larch. In addition, in selective natural forest cutting zones, we keep forests vital and sound by promoting thinning and selective cutting (thinning selected trees) within a range not exceeding their growth, as well as appropriate natural regeneration (sprouting young trees from seeds which fall to the ground naturally). Thus, we aim to achieve sustainable supply of timber from broad-leaf trees. In natural forests, a wider variety of tree species coexist than in artificial forests. Accordingly, appropriate and extensive knowledge and skills corresponding to a wide variety of species are necessary when managing natural forests. We therefore strive to improve our knowledge and skills related to natural forests through initiatives such as inviting a Swiss forester with a wealth of knowledge on the management of natural forests to teach.
In Japan, many natural forests were replaced with artificial forests in the post-war period. Therefore, the depletion of forest resources, particularly the depletion of broad-leaf trees growing in natural forests, has been a chronic problem. Accordingly, the furniture industry has been forced to increasingly rely on imported timber, which constitutes the majority of the raw materials they use, because many of their products are made of timber from broad-leaf trees. We are attempting to convert parts of artificial forests into natural ones in our efforts to restore broad-leaf tree resources. In addition, to promote the cyclical use of timber from broad-leaf trees produced in Japan, we have chosen our own offices as the places to begin. We utilized timber from broad-leaf trees produced in our company-owned forests for the tables in the company cafeteria of the Head Office, as well as the office furniture, etc. including meeting tables and chairs for Sapporo Office, where the forest management division is located.

Supplying timber from forest thinning to societySupplying timber from forest thinning to society

Forest management training taught by a forester from SwitzerlandForest management training taught by foresters from Switzerland

A big table at the corporate cafeteria of the new Head OfficeA big table at the corporate cafeteria of the Head Office

School Utilizing Timber from Company-owned Forests Opens in Hokkaido

School building using timber from our company-owned forestSchool building using timber from our company-owned forest

Raw Japanese larch logs that were cut down for maintenance of the Hayakita Forest, which is owned by Mitsubishi Mateirals Corporation, were used for the beams, columns and other members of the new school building of an integrated elementary and junior high school for compulsory education in a town opened in April 2023, where our company-owned forest is located.


2. Contributing to the Local Community
–Forests Where Local People can Relax and Interact with the Wonders of Nature–

As well as being company assets, our company-owned forests are an important element of the environment, in terms of shaping the local area. We contribute to local communities through appropriate forest management, which improves the quality of ecosystem services, including watershed protection, prevention of soil loss and recreation.
Company-owned forests located on the outskirts of urban areas meanwhile are positioned as “environmental forests,” parts of which are open to the general public to enjoy the natural environment up close. Located in the Teine area of Sapporo, Teine Forest is blessed with a slice of rich forestland that also has excellent transport access from the city center. We open up part of the forest to the people of Sapporo as a public forest, for purposes such as nature walks and camping ground. We also provide access to fields for nature activities organized by a local NPO, as a practice slope for local elementary school children to improve their skiing, and for research by universities and other institutions. That is why it is important to maintain an environment that is suitable for each of these purposes, so that everyone in the local community is able to use our company-owned forests in a meaningful way. In addition, we are proactive in activities such as thinning trees to add light to the interior of our forests, removing dangerous trees, and creating and maintaining paths in the forests. Instead of just offering our company-owned forests for use by local residents, we implement initiatives such as tree planting festivals, tree growing festivals, and other environmental events in our forests to teach local people about the value and fun that forests provide, including their biodiversity. We also actively pursue support activities in areas that were affected by natural disasters in the past. We worked on the recovery of a forest owned by Mori Town, Hokkaido, which was damaged by the typhoon in 2016. We also donated Christmas trees from our company-owned forests to local nurseries in Atsuma Town, which were affected by the Hokkaido Eastern Iburi earthquake in 2018, and continue to pursue activities including the donation of wooden graduation certificates made using the wood waste of broad-leaf trees generated in forest maintenance to preschools that use Materials Forest as a place for contact with nature.

We continue to contribute to local communities through these kinds of active initiatives and increase our efforts to make the forests of Mitsubishi Materials into valuable features of their local areas.

An environmental event making tree name plates in a company-owned forestAn environmental event making tree name plates in a company-owned forest

A Christmas tree sent to a nursery in Atsuma Town , which was affected by the Hokkaido Eastern Iburi earthquakeA Christmas tree sent to a nursery in Atsuma Town, which was affected by the Hokkaido Eastern Iburi earthquake

Providing Company-owned Forests as a Place for Local Elementary School Students to Experience and Learn about Forestry

Observing tree thinning workObserving tree thinning work

As part of our educational program for elementary schools in towns where our company-owned forests are located, we have offered our “Materials' Forests” for hands-on experience. By allowing students to observe and experience activities such as tree planting and forest thinning work, the program deepens ties between the Company and the local community.


3. Contributing to a Decarbonized Society
–CO2 Fixation–

One of the important ecosystem services of forests is CO2 fixation. As one of the largest owners of forestland in Japan, we dedicate ourselves to the steady promotion of appropriate forest maintenance, and do our level best to enhance the CO2 fixation capabilities of the trees in our forests, so that we can do our best to prevent global warming. The current CO2 fixation capabilities of our forests are estimated* to be 53,000 tons of CO2 per year (equivalent to the annual amount of CO2 emitted by approximately 27,000 people).
The ability of trees to fix CO2 peaks during the period when they are young or middle-aged, and gradually declines thereafter. That is why we make every effort to regenerate our forests, by felling and planting new trees at the right time, or through natural regeneration, in order to maintain CO2 fixation capabilities over the long term.

We also strive to fix CO2 in forests by promoting the active use of usable timber from forest thinning, which is a forest maintenance measure, instead of leaving this timber in forests. We place priority on the production of high-quality, large-diameter timber to be used over long time frames, as building materials or for furniture for instance. This is another of our initiatives for effective CO2 fixation.

  • Method of calculation
    Growth (m3) x material volume weight (t/m3) x carbon conversion efficiency x tree/trunk ratio x CO2 molecular weight / carbon molecular weight

Japanese larchJapanese larch

Relationship between Tree Age and Carbon Absorption/Emissions figure

  • Partially processed and quoted from the Japan Forestry and Forest Products Research Institute materials.


4. Conserving Biodiversity
–Maintaining an Environment Suitable for a Wider Range of Wildlife–

Our company-owned forests are extremely important as a habitat for a diverse range of wildlife. We therefore take the utmost care to ensure that our various activities, including timber production, do not have a detrimental impact on living organisms.

In particular, forest ridge and riverside areas are migration pathways for creatures. They are called green corridors because those forests are extremely important for expanding the habitat of wild animals and allowing their interactions. We therefore prohibit clearcutting these forests, in principle. We also refrain from clearcutting large areas of land even in artificial forests, where we proactively produce timber, because it may reduce biodiversity in those forests. Instead, we clearcut small, dispersed areas. In addition, we are planning not to clearcut artificial forests which are judged difficult to manage efficiently. We aim to nurture these forests into natural forests with richer biodiversity. We have also introduced trial forest maintenance methods in selected areas, aimed at conserving biodiversity. These include multi-layered forest management that prevents creating completely bare areas following felling operations, and pursuing mixed forest management between coniferous and broad leaf trees in certain areas, in order to leave naturally invasive broad-leaf trees in areas in which coniferous trees are the main user of resources, thus giving the forest a more diverse structure. By developing various types of forests in this way, we are striving to increase the diversity of the overall forest environment, thereby contributing to conserving biodiversity.
We also proactively monitor wildlife. As well as recording wildlife sightings during regular patrol activities, we have positioned a large number of wildlife survey sites in our forests, where we regularly inspect the wildlife living there and confirm the positive or negative impact of our forest maintenance. In particular, when we do forest maintenance involving felling, we separately carry out monitoring surveys before and after, to confirm that wildlife has not been affected. If any rare species are found in an area in a monitoring survey before felling, we change the time or method to one that will not affect those species, or consider the postponement of the planned maintenance.

Rare species that have been confirmed to be living in the area (most endangered species included on red lists published by the Ministry of the Environment and Hokkaido Government) are included in our own red list of rare species living in Mitsubishi Materials company-owned forests. We issue warnings to all involved parties with access to the relevant forests to conserve biodiversity, such as by holding regular training sessions for them.

Daily monitoring activitiesDaily monitoring activities

Wildlife camera trapWildlife camera trap

Japanese sableJapanese sable

Black woodpeckerBlack woodpecker

Masu salmonMasu salmon

Japanese primroseJapanese primrose

Dogtooth violetDogtooth violet

Biodiversity policy in Company-owned forests

  1. In carrying out operations, in accordance with the separately specified 'Guidelines for operations in consideration of the conservation of biodiversity', consideration shall be given to maintaining a healthy forest with a good balance of diverse vegetation and diverse stages of growth and to conserving the environment in which valuable plants and animals grow, in order to maintain and conserve biodiversity.
  2. Identify species of valuable natural vegetation and animals with high potential for growth and habitat, distribute a 'List of valuable natural vegetation and animals' to staff and contractors (workers), and have them carry it with them when they visit the site for monitoring.
  3. Promote activities that contribute to the conservation of biodiversity, such as the certification of nature symbiosis sites, in order to contribute to Nature Positive and the 30by30 target.
  4. Organize on-site training sessions by experts to improve the knowledge of staff.

(Excerpt from a company forest management and administration plan)