Over the last 60 years plastics production has increased manifold, owing to their inexpensive, multipurpose, durable and lightweight nature. These characteristics have raised the demand for plastic materials that will continue to grow over the coming years. However, with increased plastic materials production, comes increased plastic material wastage creating a number of challenges, as well as opportunities to the waste management industry. The present overview highlights the waste management and pollution challenges, emphasising on the various chemical substances (known as "additives") contained in all plastic products for enhancing polymer properties and prolonging their life. Despite how useful these additives are in the functionality of polymer products, their potential to contaminate soil, air, water and food is widely documented in literature and described herein. These additives can potentially migrate and undesirably lead to human exposure via e.g. food contact materials, such as packaging. They can, also, be released from plastics during the various recycling and recovery processes and from the products produced from recyclates. Thus, sound recycling has to be performed in such a way as to ensure that emission of substances of high concern and contamination of recycled products is avoided, ensuring environmental and human health protection, at all times.

While attention on the importance of closing materials loops for achieving circular economy (CE) is raging, the technicalities of doing so are often neglected or difficult to overcome. These technicalities determine the ability of materials, components and products (MCPs) to be properly recovered and redistributed for reuse, recycling or recovery, given their remaining functionality, described here as the remaining properties and characteristics of MCPs. The different properties of MCPs make them useful for various functions and purposes. A transition, therefore, towards a CE would require the utmost exploitation of the remaining functionality of MCPs; ideally, enabling recirculation of them back in the economy. At present, this is difficult to succeed. This short communication article explains how the remaining functionality of MCPs, defined here as quality, is perceived at different stages of the supply chain, focusing specifically on plastic packaging, and how this affects their potential recycling. It then outlines the opportunities and constraints posed by some of the interventions that are currently introduced into the plastic packaging system, aimed at improving plastic materials circularity. Finally, the article underpins the need for research that integrates systemic thinking, with technological innovations and policy reforms at all stages of the supply chain, to promote sustainable practices become established.

Circular economy (CE) is extensively discussed around the globe. Presently, discussions are mostly concerned with the importance of achieving CE and the benefits associated therewith, with the various barriers surrounding its implementation being less debated. Understanding the context in which circularity can flourish is a prerequisite in building the capabilities to deal with the multi-faceted challenges that currently hamper progress in closing the material, component and product loops. In this study, we discuss the importance of systems thinking in understanding the way resource recovery systems operate, and in promoting deep transformational change. We suggest that transformational change needs to go beyond closing materials, components and products (MCPs) loops, and promote sustainability in the way resources are exploited, used and managed throughout the system. By adopting a system of systems approach, we postulate that there are five interconnected sub-systems that need to be considered for supporting transitions to CE, namely, resource flows and provisioning service; governance, regulatory framework and political landscape; business activities and the marker; infrastructure and innovation; and user practices. This holistic approach provides a useful means to cutting through systemic complexity, and focuses on the dynamics between processes, values and actors in the value chain, and their dependence on cultural, spatial and temporal characteristics. We conclude that a systems-based approach can build up the capabilities required to identify and understand persistent linear trends and, in turn, support forward-thinking and time investment in enabling sustainable transitions. This, in turn, can help to align priorities and transform our current practices, speeding up the process of closing the MCP loops in a sustainable manner.