Technical Bulletin No. 1003: Methods for Open-Loop Recycling Allocation in Life Cycle Assessment and Carbon Footprint Studies of Paper Products
In this document, the allocation methods for open-loop recycling most frequently used in pulp and paper case studies or presented as options in the ISO standards on life cycle assessment (LCA) are presented, illustrated, discussed and compared. It is shown that the choice of one allocation procedure over another can have a significant effect on the results of an LCA. In particular, the ISO standards on LCA require that sensitivity analyses be performed when several methods seem applicable. In part because of this, LCA may not be useful for obtaining unambiguous conclusions if the objective of the LCA is to compare virgin and recycled paper. When selecting an allocation method for recycling, the following should be kept in mind: the method should be consistent with the objective of the study; the set of values inherent to the selection of the method should be transparent; the selected method should preserve mass and energy balances (with the exception of the closed-loop procedure); and a similar allocation method should be applied to both the inflows and outflows of recovered material in the system boundary.