Circular Footprint Formula: Challenges and Opportunities in Assessing the Circularity of Post-Consumer Recycled Materials for Automotive Panels

The automotive industry, at 9.7 %, drives the third largest demand for virgin plastics after the packaging and construction industries in Europe. While increasing the recycling rates for the end of life (EoL) of vehicles is important, it is also imperative to close the loop by increasing the use of post-consumer recycled (PCR) plastics. The utilization of PCR materials remains largely constrained due to olfactory limitations in interior applications and due to technical and surface performance limitations in exterior applications. Novel and scalable manufacturing technologies like co-injection molding and in-label molding can improve the surface performance whilst increasing the share of PCR materials. This also addresses the new draft on EU-Regulation on circularity requirements for vehicle design which is expected to come into effect by the year 2032. The use of PCR materials, however, creates the issue of EoL allocation in the life cycle assessment of the primary and the recycled materials between their consecutive life cycles. There are multiple EoL allocation approaches like the cut-off approach, the avoided burdens approach, the Nordic LCA guidelines recommended 50/50 approaches, the EU-JRC PEF recommended circular footprint formula, and other market-price based allocation approaches. These approaches allocate the burdens of recycling and disposal of the materials differently between its consecutive lifecycles, thus affecting the overall LCA results for the recycled material. PCR polypropylene used to manufacture automotive carrosserie, specifically the bumpers, is used as a case-study to demonstrate how value choices in the selection of EoL approach can affect the overall life cycle assessment results. Results indicate that using disparate allocation approaches could potentially yield divergent outcomes, i.e., the inconsistent use of allocation approaches in different life cycles of materials might lead to double counting or complete avoidance of environmental impacts.