In accordance with the operating philosophy of sustainable operations and green production, PSMC has moved away from the traditional recycling design mode of emission → collection → outsourcing processing. Instead, we consider the feasibility of reusing chemical waste liquids within the fab. Previously, scrubbers in the fab’s air pollution control equipment required adding chemicals to control scrubbing solution pH values. But after assessment, diluted waste sulfuric acid was found to be able to substitute for the original chemicals to control pH; and so, we installed a sulfuric acid recycling and dilution system in the fab. This has resulted in reuse of c. 1,589 tons of waste sulfuric acid from the Fab. This lessens load on the wastewater processing system, and lowers outsourcing processing costs by NT$8.77 million. Not only does this reduce purchasing of chemicals, outsourced waste processing, and carbon emissions during the transport process, but it also helps realize the Company’s policy of working hard to implement lower waste and cyclical reuse for the environment.