Material Flow Analysis for Expanded Polystyrene Packaging and Greenhouse Gas Reduction by Recycling

Many synthetic resins manufactured using foaming polystyrene (PS) have been reported, including expanded PS (EPS), a thermoplastic polymer widely used in insulation, packaging, aquaculture floats, and buoys. There has been increasing demand for packaging EPS in recent years due to the growth of online shopping and food delivery markets. However, if not adequately managed, EPS decomposes into microplastics, adversely affecting human health and the ecosystem. In this study, the material flow of EPS packaging in Korea was analyzed quantitatively according to its life cycle. In addition, greenhouse gas emissions reduction from recycling EPS was estimated using the US EPA waste reduction model WARM. In 2019, approximately 47,000 tons of EPS were sold and ultimately discharged into plastic waste streams. About 42,000 tons were recycled, of which 40,000 tons (96%) were recycled as ingots, 287 tons as pellets, and 1,521 tons as a fireresistant coating for steel frames. As a result of this recycling, 62,700 tons of CO2eq was reduced in 2019, while the cumulative greenhouse gas reduction from 2003 to 2019 was estimated to be about 592,000 tons of CO2eq. This study demonstrated the potential benefits of minimizing environmental emissions and reducing greenhouse gases through recycling. However, more detailed research is needed to ensure more effective EPS packaging management and thus further minimize potential environmental impacts and microplastic pollution, including investigations into the impacts of restrictions and bans and the consequences for marine littering.