Marine Plastic Pollution and International Trade: Legal Pathways for Sustainable Solutions

Abstract

Marine plastic pollution has emerged as a defining transboundary environmental challenge of the twenty-first century. While plastic leakage is driven largely by domestic waste mismanagement, international trade in plastic products and plastic waste plays a critical yet underregulated role in shaping material flows, incentives, and environmental outcomes. This article examines the legal interfaces between oceans law, chemicals and waste law, and international trade law to identify coherent, trade-consistent pathways for curbing plastic leakage into the marine environment. It surveys core treaty regimes UNCLOS, MARPOL, the London Convention/Protocol, and the Basel Convention (including its plastic waste amendments) and analyzes their interaction with WTO law (GATT, TBT, SPS, and SCM Agreements) and preferential trade agreements (PTAs). Using comparative illustrations from the EU Single-Use Plastics regime, shifts in global scrap plastic markets following China’s “National Sword” policy, and emerging extended producer responsibility (EPR) frameworks, the article proposes a toolbox of legally robust measures: (1) aligning trade measures with multilateral environmental agreements (MEAs); (2) harmonizing definitions and standards for recycled content and design-for-circularity; (3) leveraging TBT-compliant technical regulations, conformity assessment, and eco-labels; (4) designing pro-circular subsidies that avoid prohibited support; (5) incorporating plastic-specific chapters in PTAs; and (6) enhancing due-diligence, traceability, and digital waste shipment controls. The paper concludes with a normative roadmap for embedding trade-related measures in the prospective global plastics instrument, and a research agenda on data standardization, microplastics, and loss of plastic pellets in maritime transport.