Pitfalls of ambiguity in the development of safe and sustainable biobased plastics: How can industry and regulators better navigate this landscape?

The rapid growth of plastic production and use has triggered major environmental and regulatory challenges, including waste management, microplastic pollution, and chemical safety. In recent years, the European Union (EU) has launched policies that increasingly define, classify, manage, and restrict plastics. At the same time, the emergence of biobased and biodegradable plastics has raised new questions about how these materials may be impacted by existing legislation. How emerging biobased polymers are defined and regulated across EU legislation and inconsistencies in definitions of key terms such as biobased, bioplastic, and chemical modification have been critically assessed. To support innovation, a simplified decision tree is presented — based on existing regulatory and scientific frameworks — enabling clearer classification of polymers and synthetic polymeric microparticles (commonly referred to as primary microplastic). Unlike existing decision trees, this framework also identifies which plastic regulations apply and from which a polymer may be exempted. Case studies of cellophane, PLA/PHA, protein-based polymers, lignin, biobased microcapsules, and rubber demonstrate how the decision tree can be applied in practice, revealing ambiguities and potential misinterpretations. Biobased plastics are not automatically exempt from regulation but are generally treated like conventional plastics unless they meet strict criteria. Harmonized definitions and life cycle thinking are essential to avoid misconceptions and regrettable substitutions. Practical guidance for scientists, material developers, and regulators to navigate the evolving field of biobased plastics in the context of the EU plastics policy landscape, and advance safe and sustainable polymer innovation is provided.