This lecture covers the concepts of allocation and recycling in Life Cycle Assessment (LCA). It discusses how to allocate impacts between co-products, the importance of system boundaries, and methods for handling recycling in LCA. The instructor explains the challenges of allocation for co-products, system expansion, and the order of preference for allocation methods. Additionally, it explores closed-loop recycling, material bonuses, and the calculation of grade loss in recycling processes. The lecture also delves into energy recovery, end-of-life strategies, and the modeling of waste treatment. Overall, it provides a comprehensive overview of the key considerations and methodologies involved in addressing allocation and recycling issues in LCA.