Environmental Sustainability｜Air Pollution Control

Air Pollutant Emissions

Nuvoton rigorously complies with governmental environmental regulations and refers to international standards, demonstrating a commitment to the ongoing reduction of pollutant emissions. The primary air pollutants produced by Nuvoton stem from its production processes and include Volatile Organic Compounds (VOCs), nitrogen oxides, sulfur oxides, ammonia, chlorine, hydrochloric acid, nitric acid, and phosphoric acid, among others. To effectively manage these pollutants, the Company addresses them at the source by enhancing processes to decrease the concentration and volume of waste gas. Nuvoton implements suitable treatments for various waste gases, tailored to their specific characteristics. The Company's air pollutant treatment system runs continuously around the clock, with constant monitoring of its operational status to guarantee proper functioning. Below are the treatment methods for various types of waste gas:

1.In the exhaust gas, general acidic and alkaline gases are discharged to the central gas scrubber for neutralization.

2.Certain flammable, toxic, and FC-containing exhaust gases first undergo high-concentration treatment at the process equipment's on-site air treatment facility (Local Scrubber) using adsorption, combustion, electric heating, or washing systems to effectively mitigate hazards. The treated gases are subsequently discharged to a central exhaust scrubber for neutralization.

3.Exhaust gases containing volatile organic compounds are first adsorbed by a zeolite rotor before being directed to a direct-fired oxidation furnace for incineration. High-boiling-point organic exhaust gases are collected through condensation based on temperature differentials.

In addition to continuous monitoring within the plant, certified laboratories are commissioned annually to conduct tests, and the results are reported to the regulatory authorities. The test items include non-methane hydrocarbons (NMHC), acid and alkaline gases, such as sulfuric acid (H₂SO₄), hydrochloric acid (HCI), nitric acid (HNO₃), hydrofluoric acid (HF), phosphoric acid (H₃PO₄), and ammonia (NH₃), etc. Historical actual test results from Nuvoton show that the concentration of air pollutant emissions consistently remains below the exhaust emission standards.

¹  The survey scope of Nuvoton Taiwan is the Yanshin plant, while Nuvoton Japan reported no detection(ND) of VOC and PM values in 2024.

²  The data information here has been recompiled and the adjustment instructions compared with the previous year's report are detailed in Appendix 3.