As part of the European Green Deal, the European Commission announced the adoption of its Circular Economy Action Plan in March 2020 (FPF reported). The plan aims to reduce packaging waste, increase recyclability, and remove hazardous chemicals from product life cycles. Three recent reviews published over the last two months have focused on different aspects related to addressing plastics in a circular economy. The articles cover (i) the research status and gaps related to plastics in the circular economy, (ii) plastic food packaging waste generation, recycling, trade, and fate as marine litter with a focus on the Netherlands, as well as on (iii) food safety hazards emerging in a circular economy.
In an article published on May 31, 2022, in the Journal of Cleaner Production, Sarah King and Katherine E.S. Locock from CSIRO Manufacturing, Australia, presented the methodology and outcome of their semi-systematic review on plastic and the circular economy. They aimed to assess the current research status on the topic and to develop a conceptual framework for plastics in the circular economy.
For this purpose, King and Locock searched the Web of Science core collection database for literature published in English between 2000 and 2021 and containing the terms ‘circular economy’ and ‘plastic’. Duplicate removal resulted in 448 publications which they subjected to further analysis, including coding. Articles were coded according to sixteen circular economy stages (e.g., avoid, feedstock, manufacturing, consumption, reuse, mechanical recycling), seventeen polymer resin types (e.g., polyethylene, multilayer plastics, bioplastics, microplastics), plastic use categories, and first author country. During the coding process and framework refinement, ambiguous articles were removed, resulting in 391 articles that were subsequently analyzed.
King and Locock found that the literature published on the topic of ‘circular economy’ and ‘plastic’ has increased rapidly over the last years, especially with first authors coming from Europe and the Americas, reaching roughly 160 studies published in 2020. They also reported that they have developed and validated a circular economy framework specifically for plastics including the sixteen stages. The authors combined the sixteen stages into six key areas and determined the research interest for each area. Their results showed that published literature has focused on waste (49%) and recycling (26%), meaning the end of the plastics supply chain, while much less focus has been placed on interventions at the early stages including production (8%) and use (9%). The authors think that “the ultimate goal to realizing the circular economy for plastics is to eliminate the stages assigned to waste – disposal, waste to energy and leakage, with greater emphasis on improved product design, reuse and recycling.”
Importantly, 27% of the reviewed articles could not be assigned to “a clearly defined circular economy stage” and, thus, were placed in the “system category.” Furthermore, the authors reported that the majority of the reviewed studies did not focus on a certain resin type or plastic use category but rather approached the topic of a circular economy for plastics in a generalized way. Kind and Locock concluded that their developed framework “encompasses the full breadth of interventions across the supply chain” and is thought to address and conceptualize “a circular economy for plastics in both research and policy settings.”
Another finding within the study was that most previously published literature on plastics and a circular economy focused on the recycling stages. However, the current way of dealing with plastic and recycling is noted to not be working, with only 9% of all plastics being recycled and 22% being disposed of in an uncontrolled manner including leakage into the environment as reported by the Organization for Economic Co-operation and Development (OECD) (FPF reported and here). In a review article published on July 8, 2022, in the peer-reviewed journal Resources, Conservation & Recycling, Nicolas Navarre from Leiden University, The Netherlands, and co-authors, reported that Dutch plastic food packaging meant for recycling is leaked into the marine environment.
The scientists investigated how much of the plastic waste generated by Dutch food consumption is ending up in the marine environment. To first estimate the amounts of plastic packaging used in a Dutch diet, they combined data on food consumption, food waste, and plastic packaging. Subsequently, they assessed the fate of the plastic food packaging waste based on waste management data, including waste trade and litter. Navarre and co-authors calculated that on average 2.1% of the Dutch diet is plastic packaging (i.e., 2.1 g per 100 g of food), resulting in a yearly plastic food packaging waste generation of 296 kt. Of these 296 kt, 37.2 kt were estimated to be exported out of the European Union, and 6.5 kt calculated to leak into the oceans. Leakage would mainly result from plastic waste exports (78%) and only partly due to domestic littering (22%). Most of the Dutch plastic waste is exported to Asia.
The authors concluded that “despite being a high-income nation with a post-consumer plastic packaging waste network reporting a 78% recycle rate, Dutch plastic food packaging waste is leaked to the marine environment at a globally average rate, raising questions about plastic recycle rate metrics and Dutch/EU plastic waste export policies.” Since soft drinks, grocery, and dairy products, mainly made from polyethylene (PE) and polyethylene terephthalate (PET), were found to be the main contributor to ocean debris for the Netherlands, they further suggested developing solutions to reducing the plastic packaging used within these food groups.
Some countries, such as Australia, have declared a ban on the export of recycled waste (FPF reported), and in the US calls have been strong to improve recycling infrastructure to be able to handle the domestic waste the country generates (FPF reported). In March 2022, 175 nations agreed to create an international, legally binding treaty by the end of 2024 to end plastic pollution (FPF reported).
Besides plastic pollution, another concern raised in the context of recycling is the presence of hazardous chemicals in plastic waste that may still be present in recycled products (FPF reported). In a review article published on June 21, 2022, in the journal Food Research International, Marlous Focker from Wageningen Food Safety Research, Netherlands, and co-authors summarize known and potential food safety hazards that may emerge with the transition towards a circular food system. In their review, they focus on a circular biobased economy looking at four production domains, including packaging, plant production, animal production, and aquaculture. They provide examples of improved circular food production systems and potentially related hazards.
Concerning packaging, Focker et al. described that food packaging needs to be reduced, reused, or recycled to meet the needs of a circular economy. As health concerns related to packaging recycling, they pointed to chemical contaminants present in the primary product and also being reintroduced in the recycled products, even leading to their accumulation. Examples include the accumulation of heavy metals or metalloids in recycled aluminum or steel cans, mineral oil hydrocarbons (MOH) in paper (FPF reported), and polymer degradation products and additives in recycled plastics. They find “the absence of knowledge of potential risks is a true hurdle for a rapid acceptance of recycled plastics to support the aims for sustainable food contact materials.” The Food Packaging Forum (FPF) has published fact sheets that provide an overview of the different food packaging materials, also looking at their recyclability and chemical safety (FPF reported).
Summarizing their findings for all four domains, Focker and co-authors find that literature on the topic is scarce and further studies are needed to clarify hazards in food and feed production systems, as well as to control and mitigate them. Most recent research has been focused on pharmaceuticals, dioxins, heavy metals, polychlorinated biphenyls (PCBs), and pathogens, while other chemicals and microbiological hazards have largely been neglected. The researchers emphasized that “a circular redesign of our primary production systems is needed and the principles of safety by design should be included in the redesign of our future food production systems.”
References
Focker, M. et al. (2022). “Review of food safety hazards in circular food systems in Europe.” Food Research International. DOI: 10.1016/j.foodres.2022.111505
King, S. and Locock, K. E. S. (2022). “A circular economy framework for plastics: A semi-systematic review.” Journal of Cleaner Production. DOI: 10.1016/j.jclepro.2022.132503
Navarre, N. et al (2022). “Recycled plastic packaging from the Dutch food sector pollutes Asian oceans.” Resources, Conservation & Recycling. DOI: 10.1016/j.resconrec.2022.106508
