Options for the comparison of process design alternatives in the context of regional toxicological impacts

Process design alternatives can be compared in terms of effluents and energy consumption. Approaches can be used to account for differences in regional exposure and associated toxicological effect parameters. A significant number of approaches have been published in the literature to achieve these objectives. However, selection of a methodology is typically subjective and influenced by resource availability (knowledge and economic). Often criteria are not used to guide designers in their selection or to steer associated research activities. In this paper, the merits and applicability of five types of methodology are considered with the help of a hierarchical framework.