Comparative Life Cycle Assessment in the plastic sector: A systematic literature review

European institutions have recently introduced new environmental policies relevant to the plastics sector. This could accelerate the transition to alternative materials. However, this transition needs to be based on reliable environmental assessments. A systematic review of the literature is presented with the aim of investigating the diffusion and the methodological setup of Life Cycle Assessment (LCA) in a comparative context for plastics and their alternatives. Emphasis was placed on the ability to support decision making, and a new procedure was proposed to assess whether the studies can support in the selection among alternatives. For this purpose, 79 articles were analyzed. The analysis showed that LCA is by far the most widely used environmental sustainability tool, although there is a lack of homogeneity in its application. Subjectivity remains in the definition of the methodological approaches, which are rarely discussed in the interpretation. The need for a comprehensive analysis often leads to trade-offs between environmental aspects which should be handled quantitatively and transparently, but weighting is rarely applied. However, weighting procedures may not be conclusive if different methodological approaches lead to conflicting findings. Many of the recommendations formulated involve testing several methodological combinations, requiring a multi-criteria analysis tool to aggregate the results.