This report focuses on renewable carbon in recycling scenarios and the key challenges in LCA and carbon footprint assessments. It examines system boundaries, allocation methods, and biogenic carbon accounting approaches, highlighting their influence on sustainability evaluations. The report emphasises the cut-off and avoided-burden approaches for recycling while recommending the -1/+1 method for biogenic carbon transparency. However, it also identifies contradictions between LCA results and broader sustainability goals, such as the EU waste hierarchy, which prioritises recycling. To address these inconsistencies, the report suggests integrating LCA with additional sustainability metrics like land use and recyclability. Ultimately, refining these methodologies will enhance the accuracy and reliability of environmental assessments for bio-based and recycled materials.