Against the backdrop of escalating risks from global climate change, iST attaches great importance to the impact of its operational activities on the environment. The Company continues to drive GHG emission management and reduction initiatives to mitigate its impact on the climate and environment. The Company promotes ecological quality by implementing green production, strengthening low-carbon management, and enhancing energy efficiency, thereby fulfilling its corporate social responsibility and advancing toward the goal of sustainable operations.

Since 2021, iST has established a systematic GHG inventory and management process in accordance with ISO 14064-1 and the Greenhouse Gas Verification Guideline of the Ministry of Environment. In 2021, the self-inventory of GHG emissions for Hsinchu Plant 1 was completed, and in 2022, the scope of the inventory was expanded to cover the entire site. Since 2023, GHG inventory results have been verified by a third-party verification company to ensure the integrity and credibility of the data. These inventory results serve as a critical foundation for the Company's GHG reduction measures and environmental management decision-making.

iST adopts operational control as the organizational boundary for its GHG inventory. In 2025, the inventory sites included Hsinchu Plant 1, Hsinchu Plant 2, Puding Plant, Dean Plant, Taiyuan Plant, Changyi Plant, Neihu Plant, and Zhongxing Plant. GHGs included are CO₂, CH₄, N₂O, HFCs, PFCs, and SF₆.

The total GHG emissions (as shown in the table below) include: Scope 1 (Category 1) direct GHG emissions were 1,706 tCO₂e, accounting for 6.79%, primarily originating from equipment refrigerants and company vehicles. Scope 2 (Category 2) energy indirect GHG emissions were 22,860 tCO₂e, accounting for 91%, mainly from the use of purchased electricity. Category 3 and Category 4 other indirect GHG emissions were 554 tCO₂e, accounting for 2.21%, resulting primarily from employee commuting, waste disposal, and transportation. iST's GHG reduction strategy focuses on improving electricity efficiency and reducing consumption. In 2025, GHG emissions (Scope 1 and Scope 2) increased slightly by 1,899 tCO₂e compared to 2024. However, with overall revenue increasing by 14.16%, the intensity of GHG emissions decreased by 18.52% compared to the 2022 base year. This achieved the goal of reducing the intensity of GHG emissions by 8%. In 2025, six energy-saving programs were implemented, saving a total of 2,829.195 MWh (calculated via self-estimation), equivalent to a reduction of 1,341.038 tCO₂e.

iST's energy consumption includes electricity, gasoline, and diesel, with no other energy sources such as district heating utilized. These are sourced from government-owned power plants and gas stations. Electricity is the primary energy source, while gasoline is used for company vehicles and diesel for backup generators. The Company began using renewable energy in 2025. Electricity and energy intensity are detailed in the table below.

iST implemented six projects to improve energy efficiency and replace old plant equipment in 2025 (as shown in the table below), with a total investment of NT$ 26,026 thousand. This resulted in a 7.92% reduction in the intensity of power consumption compared to 2022, achieving the target of a 5% reduction. Furthermore, the solar renewable energy system at iST's Hsinchu Plant 2 was commissioned in 2025. Moving forward, the Company will continue to enhance its energy efficiency and adopt energy-saving and carbon reduction measures—such as selecting renewable or alternative energy sources—to contribute to sustainable development on Earth.