In the nickel foam system, the electricity production contributed significantly to the total impact of the system. From this process, emissions of mercury to air (23%), Polychlorinated dibenzo-pfurans to air (35%), chromium to freshwater (18%) constituted the main flows. The production of the platinum electrodes was also an important process for the systems human toxicity (cancer), in which the emissions of mercury (33%), nickel (26%) to air and chromium (18%) to freshwater contributed the most. Emission of chromium (76%) to freshwater from the ethanol production was also significant for the systems human toxicity potential.