Alain Dubreuil, Lindita Bushi and Steven B. Young
Comparative LCA studies of identical auto parts conducted by different LCA practitioners can lead to significantly different results and recommendations. While each of the LCA studies may be compliant with the International Organization for Standardization (ISO) 14040 series of LCA standards, discrepancies in modeling, data sources and in parameters can explain significant variations in the results.
Under the initiative of Natural Resources Canada, the CSA Group produced an LCA guidance document of Auto parts. The initiative took over two years and included 14 technical experts from material industries (including steel, aluminium, magnesium, plastic and composites), auto part manufacturing and LCA experts. The document was peer reviewed for technical accuracy, conformance with ISO 14040/44 principles, and general relevance and applicability.
The guidance document establishes rules and requirements for conducting comparative LCA studies with the objective of providing clear and consistent guidance for assessing potential environmental impacts throughout the cradle-to-grave life cycle of an auto part with a focus on weight differences between design options.
The guidance document includes significant consideration of the specification of performance characteristics and description of an auto part, definition of the functional unit and the reference flow, system boundaries, predetermined parameters, data quality requirements, allocation procedures for recycling, model to calculate the life cycle mass-induced fuel change of the auto parts , sources of inventory data for materials, life cycle impact assessment (LCIA) categories and life cycle inventory indicators, and a transparent platform for calculating and communicating the environmental indicator results.
The guidance document is tailored for internal combustion engine vehicles in the North American context and covers all U.S EPA Passenger Vehicle Size Classes (sedan, station wagons, pickup trucks, vans and sport utility vehicles-SUVs). The framework of the guidance document is adaptable to include advanced powertrains (e.g., hybrid and electric). Adjustment would be required for application in other regions.