Plastics are versatile materials that are used across multiple applications and sectors delivering many benefits to society. Plastics may include thousands of different chemicals, including some that raise particular concern and may have negative impacts on human health and the environment if not properly managed. Identifying these substances becomes even more challenging when materials are recycled, as chemical information may be incomplete or lost along value chains and new contaminants, degradation products or reaction products can emerge during use and recycling. The heterogeneity of plastic waste, with limited source separation of closed loop systems, increases this complexity. This report provides an overview of the chemical considerations integrated into standards, certifications and quality control measures for recycled plastics, and examines analytical techniques used to characterise the chemical content of secondary materials. Overall, ensuring chemical safety in recycled plastics requires an integrated approach combining harmonised international standards, robust analytical techniques, chemical traceability systems, economic incentives and research collaboration. Together, these elements can support safe and sustainable circularity while maximising recycling rates.
