Purpose: Emerging technologies are addressing current challenges to shift from a linear to a circular economy. However, the consideration of social aspects in this context is limited, and the prioritization of indicators appears arbitrary in the absence of clear and robust selection criteria. Following social life cycle assessment (S-LCA) principles, the aim of this paper is to guide the selection and inventory of social indicators based on a case study on evolving flexible packaging within the European circular economy. Methods: To achieve the objective, the study involves several steps, including conducting a systematic literature review to identify key stakeholders, impact subcategories, indicators, and inventories for circular flexible plastic packaging. Multi-criteria decision analysis (MCDA) is applied to preselect a set of indicators, followed by stakeholder engagement in prioritizing impact indicators through participatory methods. Subsequently, a data collection procedure was established. Results and discussion: This paper presents a materiality ranking for 19 social indicators tailored to the emerging circular flexible packaging. The result is a prioritization of nine of these indicators, including Existence of record of proof of age, Percentage of workers who are paid a living wage or above, and Existence of certified environmental management system. These nine indicators form the basis for the collection of respective inventory data for an entry-level assessment. Furthermore, guidelines on 11 procedural steps were formulated based on these findings. Moreover, challenges of synonymity and inconsistency in S-LCA terminology, besides inaccessible inventory data especially in the context of evolving recycling technologies, are identified as substantial barriers in the effort to streamline and perform S-LCA. Conclusions: The paper concludes that prioritizing indicators is essential for entry-level and prospective assessments, especially when time and data are limited. Additionally, using primary inventory data to evaluate the foreground system and its direct impacts on stakeholders promotes accountability and corporate social responsibility. Furthermore, a set of procedural steps, from defining the system boundary to preparing the data questionnaire, serves as a valuable resource for practitioners across diverse industries. Recommendations: In future research, these nine prioritized indicators can be applied to assess the social performance of various case studies along the value chain of circular flexible plastic packaging, covering food and non-food applications. In addition, the methodological guidelines for selecting and prioritizing indicators can be replicated across multiple industry sectors. Moreover, research effort should be directed towards establishing a methodological framework for prospective S-LCA in the context of emerging technologies.

Integrating recyclates into food packaging is key towards circularity while meeting functionality and safety requirements; however, associated environmental impacts remain underexplored. This gap was addressed through a cradle-to-gate life cycle assessment, using the Environmental Footprint method, along with substitution and cut-off approaches for handling the multifunctionality of recycling. Recyclates were derived from polyethylene (PE)-rich household food packaging waste, purified via delamination-deinking. Firstly, results show that shifting from virgin multi-material to mono-material multilayer structures with or without recyclates, while maintaining functionality, offers environmental benefits. Secondly, recyclates should sufficiently substitute virgin materials in quantity and quality, decreasing the need for primary plastics and avoiding recyclate incorporation without functionality. Otherwise, thicker laminates are obtained, increasing processability challenges and environmental impacts, e.g., 12% for particulate matter, and 14% for mineral-metal resource use when the recycle content rises from 34 to 50%. Thirdly, a fully closed loop for flexible food packaging is not yet feasible. Key improvements lie in reducing residues generated during recycling, especially in delamination-deinking, lowering energy use in recompounding, and using more efficient transport modes for waste collection. Further research is essential to optimise the innovative technologies studied for flexible food packaging and refine them for broader applications.

Purpose Emerging technologies are vital for transitioning to a circular economy. Regarding circular flexible plastic packaging, challenges encompass enhancing collection infrastructure, sorting, recycling, and adopting circular design principles to enable the circular use of post-consumer recyclates. However, integrating social aspects and guidance on prospective Social Life Cycle Assessment (S-LCA) remains limited. This study develops methodological strategies to address key challenges identified during a social entry-level assessment, using circular flexible plastic packaging as a case study. Methods The methodology is guided by the design science research approach, which follows key phases: problem identification, objective definition, solution development, demonstration, and evaluation. In this context, methodological strategies are developed as output knowledge based on problems identified through the S-LCA, which serves as input knowledge. The S-LCA process includes key steps—goal and scope definition, life cycle inventory data collection, impact assessment, and interpretation of results. The case study includes various stages of the innovative life cycle, including novel tracer-based sorting, emerging recycling technologies such as selective dissolution and/or deinking and delamination, deodorization and packaging laminate production in Europe, all integrated into a hypothetical (future) industrial system. The inventory is predominantly based on primary data, with a focus on the foreground system and nine prioritized indicators relevant to the entry-level reference scale impact assessment. Results and discussion This led to the compilation and development of 15 methodological strategies tailored to the assessment of emerging technologies. These include, for example, narrowing the scope, using proxy data through upscaling techniques, applying targeted normalization methods, conducting iterative data updates, and prioritizing the evaluation of processes with accessible primary data. These strategies could guide S-LCA practitioners across various industry sectors in evaluating the social performance of emerging technologies. The results of the S-LCA show the primary social hotspots as the indicator Existence of a record of proof of age and Existence of certified environmental management system. Hotspots are respectively attributed to data gaps for the supply chain and the resource constraints of small and medium enterprises. Conclusion In conclusion, the study shows that S-LCA of emerging technologies faces specific challenges, particularly limited data availability and complex value chains, requiring systematic strategies, including input from experienced stakeholders, to estimate social effects of integrating novel technologies. Future studies across diverse sectors can help validate, refine, and expand these approaches to strengthen their broader applicability and contribute to the development of a methodological framework for prospective S-LCA.