The major contributors for M1 are coal-based electricity and PMMA-co-PCMSt synthesis (Fig. ). In comparison, major contributors for M2 are electricity, PMMA-co-PCMSt, IPA, and H3CO-PEG-NCO (Fig. ). Both M1 and M2 show greater impacts on resources and human health than on ecosystem quality, which can be explained by the use of electricity from conventional energy sources (fossil fuels) and the associated hazards during mining/extraction, transportation, processing, combustion, and waste disposal.