OPSC added VOC prevention and control facilities in 2021. With the use of catalytic oxidation, the waste gas is pumped into the new system through suction ventilator. With added pressure and oxygen, the waste gas goes through the steam heater, plate heat exchanger and electric heater to reach the desired temperature. The catalyst transforms the VOCs into CO₂ and water. The purified waste gas is sent to the alkali washing tower to be scrubbed and emitted after secondary purification. After the oepration began in 2021, the concentration of VOCs has dropped considerably. In 2021, the air pollutants emitted reduced by 13% compared to 2020, keeping the emission far below regulatory limits. Total investment for this project amounts to NT$73 million.