Use of the life-cycle assessment (LCA) toolbox for an environmental evaluation of production processes

Green chemistry not only emphasizes the central production process of the "green" chemical, but it ultimately requires a life-cycle conceptual approach for each chemical product. A life-cycle conceptual approach comprises the consideration of all stages along the life cycle of a chemical (i.e., raw material extraction, pre-production, production, use, recycling, and disposal) as well as the consideration of environmental impacts caused by by-products and auxiliaries (such as solvents and additives, but also technical facilities which have to be provided to produce the green chemical). A significant improvement in the evaluation of green chemical products can be approached by the complementary use of the methodologies of life-cycle assessment (LCA) and risk assessment. The use and combination of both methodologies can be performed by a separate use of the instruments (depending on the scope, definition, and application of LCA), an iterative use of LCA and risk assessment, or a complete integration of both instruments. Pros and cons of these approaches are discussed.