Facility arrangements and the environmental performance of disposable and reusable cups

Abstract

This paper integrates two complementary life cycle assessment (LCA) studies with the aim to advice facility managers on the sustainable use of cups, either disposable or reusable. Study 1 compares three disposable cups, i.e., made from fossil-based polystyrene (PS), biobased and compostable plastic (polylactic acid; PLA) and paper lined with PLA (biopaper). Study 2 compares the disposable PS cup with reusable cups that are handwashed or dishwashed. Existing LCA studies show inconsistent and sometimes conflicting results, due to differences in used data and modeling choices. The comparison of disposable cups, study 1, deliberately applied multiple inventory data sets for relevant life cycle processes and multiple crediting principles for recycling. Included waste treatment options in study 1 were incineration, recycling, composting, and anaerobic digestion (last two not for the disposable PS cup). The PS cup is next compared with handwashed and dishwashed reusable cups (study 2). LCAs for the reusable cups use single data sets, and explore the influence of an increasing number of reuses. Cup LCA results were only compared within, and not across impact categories. All data relate to cups used with hot beverage vending machines in Dutch office settings. Impact results for each disposable cup show large and overlapping spreads. This prevents identifying a preferable disposable cup material, though still allows cautious preferences about waste treatment processes. Composting biocups is less good than other waste treatment processes. Average impact results for anaerobic digestion perform in almost all impact categories better than incineration for the PLA cup. Average impact results for recycling perform slightly better than incinerating for both biocups, but not for the PS cup. This comparison is affected, however, by the relatively large credits for avoided Dutch electricity production. Impact results for reusable cups do not perform better than disposable cups if both are used once. Impact results for the reusable cups contain large uncertainty due to widely varying user behavior. Overall results do not allow any preference for one of the disposable cups or for disposable versus reusable cups. All cups can be used for more than one consumption. This gives a considerable environmental gain for the second and third hot beverage consumption with all cups. Facility managers can encourage a second or third serving with the same cup by financial incentives, only putting on dishwashers around noon and after working time, and/or consumer awareness activities.