Mapping Flows, Stocks, Plastic Emissions, and Greenhouse Gas Emissions of Polyurethanes: Decoding Challenges and Pollution Prevention Pathways in China

Global demand for polyurethanes (PUs) has steadily been increasing. However, knowledge about PUs' anthropogenic cycles and greenhouse gas (GHG) emissions remains incomplete, hindering effective decision-making. This study employs dynamic material flow analysis to trace PU cycles in China (accounting for 45% of the global market in 2022) from 1958 to 2022, combined with scenario analysis for pollution mitigation. Given the technological advancements in PU production processes, the production volume of PUs in China in 2022 was 11 times that of 2000. The in-use stocks of PUs surged to 9.09 × 10¹⁰ kg in 2022, with the construction sectors contributing over 30.0%. The textiles, apparel, and footwear sector generated the greatest volume of PU waste, accounting for 41.4% of the total in 2022. Approximately 65.5% of PU plastic emissions were microplastics, mainly concentrated in soil. The production stage, especially the production of PU foams (1.88 × 10¹⁰ kg CO₂e in 2022), dominated the total GHG emissions. Scenario analysis suggests that combined interventions targeting all stages could reduce PU plastic and GHG emissions by over 30.0% and 15.0% in 2060, respectively. The findings offer data-driven insights for the sustainable development of the PU industry and combating the global plastic crisis.