1 Introduction
2 Co-product allocation and its use in agricultural LCA
4.3.4.2 Allocation procedureThe study shall identify the processes shared with other product systems and deal with them according to the stepwise procedure presented below.a) Step 1: Wherever possible, allocation should be avoided by1) dividing the unit process to be allocated into two or more sub-processes and collecting the input and output data related to these sub-processes, or2) expanding the product system to include the additional functions related to the co-products, taking into account the requirements of 4.2.3.3.b) Step 2: Where allocation cannot be avoided, the inputs and outputs of the system should be partitioned between its different products or functions in a way that reflects the underlying physical relationships between them; i.e. they should reflect the way in which the inputs and outputs are changed by quantitative changes in the products or functions delivered by the system.c) Step 3: Where physical relationship alone cannot be established or used as the basis for allocation, the inputs should be allocated between the products and functions in a way that reflects other relationships between them. For example, input and output data might be allocated between co-products in proportion to the economic value of the products. (International Organisation for Standardisation 2006b). |