A new study published in Cell Reports Sustainability (https://www.cell.com/cell-reports-sustainability/fulltext/S2949-7906(26)00228-4) presents a comprehensive, trade-linked probabilistic material flow analysis (PMFA) of expanded polystyrene (EPS) in China. Conducted by researchers of the team of Prof. Li Jinhui at Tsinghua University's School of Environment, the study covers the full lifecycle of EPS in 2022 and 2023, from virgin resin production through manufacturing, consumption, and waste disposal. It also maps China's role in the global EPS trade network.

The research is a core outcome of the SINOPLAST II project, a Sino-Norwegian cooperation initiative aimed at reducing plastic and microplastic pollution. Supported by the Norwegian Ministry of Foreign Affairs and the Ministry of Commerce of China, the implementation of this project is leaded by the Basel Convention Regional Centre for Asia and the Pacific (BCRC China) together with the Norwegian Institute for Water Research (NIVA), with partners from China and Norway. The study supports SINOPLAST II's objectives by providing the evidence base needed to identify priority areas within the EPS supply chain and inform targeted interventions.

· Production: China's EPS domestic production reached 3.58 Mt in 2022 and 3.94 Mt in 2023.

· Recycling: Secondary production accounted for only 25% of total production in 2022 and 28% in 2023.

· Consumption: Packaging dominates at 56% of domestic consumption, followed by building and construction at 25%.

· Waste management: Incineration accounted for 51% (2022) and 49% (2023) of post-consumer EPS fates. Landfill and mismanagement made up most of the remainder.

· Trade: China's net exports of EPS reached 659.7 kt in 2022 and expanded to 828.5 kt in 2023. Finished product exports grew to 507.9 kt.

The study uses a probabilistic material flow analysis framework that incorporates parameter uncertainty through Monte Carlo simulations with 10? iterations. The model includes five lifecycle stages: production, manufacturing, consumption, waste collection, and waste management. Trade flows are integrated at multiple points, including primary resin, semi-finished components, finished goods, and recyclable materials.

This approach allows the researchers to isolate EPS from general-purpose polystyrene. This distinction is important because the production processes, applications, and recycling patterns for foamed EPS differ from those of other polymers. The study provides a detailed sectoral breakdown, covering home appliances, e-devices, construction, food-related applications, and other products.

 

China's EPS production is dominated by virgin material. Secondary production from recycling constitutes less than one-third of total output. The consumption sector is heavily concentrated in packaging, which accounted for over 56% of domestic consumption in both years. Within packaging, household and electronic appliances constitute the largest flows. Televisions represent the single largest appliance subcategory, followed by air conditioners, refrigerators, washing machines, and freezers.

Building and construction represents the second-largest consumption sink, contributing approximately 25% of domestic consumption. This sector accumulates the highest in-use stock, with 474.9 kt in 2022, 50% of total EPS stock in use. This reflects the long service life of insulation materials and their potential as a future waste stream.

The study notes that most EPS packaging has a lifetime of less than one year. This means it rapidly enters the waste stream and contributes to environmental externalities. China has mandated manufacturers to adopt green design and increase recycled content in non-food-contact packaging through the 14th Five-Year Plan for Plastic Pollution Control. However, the packaging sector remains a significant source of environmental pollution.

  

The analysis shows that the waste management system remains largely linear. Incineration dominates post-consumer EPS disposal, accounting for 51% in 2022 and 49% in 2023. Landfill rates were 9% and 8% respectively. Together, approximately 60% of post-consumer EPS was directed to final disposal sinks in 2022, decreasing only slightly to 57% in 2023.

System losses across the lifecycle totaled 25 kt in 2022 and 27 kt in 2023. More critically, the mismanagement rate of 8–9% represents EPS that is neither captured nor properly managed. For a lightweight, friable material, this fraction has a high probability of entering the environment as litter or macroplastics, which fragment into persistent microplastics.

This pattern aligns with broader waste management trends in rapidly urbanizing economies. Incineration capacity is often prioritized to reduce landfill volume and generate energy, sometimes at the expense of developing material recycling streams. EPS faces structural challenges due to its low density and high volume, which make collection and transport economically difficult.

 

China's EPS trade patterns show a substantial and growing net export surplus. These surplus shapes the geography of end-of-life responsibility. In 2023, China's exports of finished EPS products reached 507.9 kt. The United States was the largest trading partner, accounting for 29.7% of China's finished EPS exports. Other significant markets include Japan (50.4 kt), India (24.7 kt), and Saudi Arabia (21.1 kt).

The study emphasizes that this export-oriented system represents a transfer of embedded material to consumer nations. While China's domestic post-consumer EPS recycling is growing modestly, overall global circularity for EPS is constrained by the aggregation of national waste management systems across both producing and consuming countries. The researchers argue that enhancing EPS circularity requires accounting for these transnational material flows. This includes developing harmonized metrics to measure embedded emissions and resource use in traded plastics.

 

The study proposes several policy and market measures to improve EPS circularity.

Policy-led measures include mandatory minimum recycled content requirements for non-food-contact EPS packaging, extended producer responsibility (EPR) schemes that assign physical and financial responsibility for end-of-life EPS to packaging manufacturers, and a packaging consumption tax to internalize environmental costs.

Market-led interventions must address structural barriers to recycling. These include the low density and high volume of post-consumer EPS foam, which make collection and transport difficult. Investments in dense-packing and cold-compression technologies at collection points, supported by government subsidies or public-private partnerships, could reduce logistics costs and enable recycling at scale. Improvements in sorting infrastructure are also critical, as EPS is often contaminated or incorrectly sorted.

Chemical recycling technologies, including pyrolysis and depolymerization, offer a pathway to convert low-quality or contaminated EPS waste into high-value monomers or chemical feedstocks. However, these technologies remain capital-intensive and energy-demanding. Their deployment in China would benefit from targeted R&D funding, pilot demonstration projects, and integration with existing petrochemical infrastructure.

The study concludes that achieving circularity for EPS will depend not only on policy intervention but also on comprehensive investment in collection infrastructure, advanced sorting technologies, and chemical recycling pathways. Without these parallel efforts, policy ambitions for lightweight plastics like EPS may remain difficult to achieve.

The researchers call for moving beyond national circularity targets to integrate global extended producer responsibility and end-market pull mechanisms. This requires that final consumer markets bear a significant responsibility. The effectiveness of their domestic waste management infrastructure, recycling policies, and market demand for recycled content directly determines the fate of a substantial portion of globally produced EPS.

As the world's largest producer and exporter of EPS, China's management of this material has global implications. The study provides an evidence-based framework to inform circular economy strategies and policy interventions. It establishes a foundation for transitioning toward a more sustainable plastics economy in China and globally.