Table 1. An analytical framework for comparing CCU LCA guidelines

Category	Description
Background & purpose	Policy and institutional context in which each guideline was developed, including its purpose and intended scope of application.
System boundary and functional unit	Criteria for setting system boundaries and consistency of functional units (e.g., cradle-to-gate, cradle-to-grave).
Multi-functionality	Approaches for handling multi-functionality issues (e.g., system expansion, physical allocation, economic allocation).
GHG reduction accounting	Methods for calculating GHG mitigation, inclusion of avoidance credits, and approaches for defining comparative products.
Impact assessment methodology	LCIA methodology, category selection, and criteria for the use of GWP values.
Data requirement	Data sources, cut-off criteria, representativeness management, and methods for handling uncertainty