Cradle-to-grave life cycle assessment of single-use cups made from PLA, PP and PET

Abstract

Polylactide (PLA) is both bio‐based and biodegradable and has therefore attracted increased attention for single-use plastics applications. Under the context of the recent EU Plastics and Bioeconomy strategies, this study uses life cycle assessment (LCA) to assess the environmental footprint of single-use drinking cups made from PLA, including 13 environmental impact categories. Land use changes (LUCs) were assessed based on a deterministic model. The manufacturing phase was modeled based on primary production data stemming directly from the industry. The end-of-life (EoL) impacts were assessed using the EASETECH. PLA cups were then compared with their petrochemical counterparts polyethylene terephthalate (PET) and polypropylene (PP) cups. Based on the available data quality of the petrochemical polymers, six impact categories were compared. For PLA cups, the process energy use in the conversion from biomass to PLA polymer was identified as the main environmental hotspot, followed by the electricity consumption of thermoforming of the cups. It was found that the biomass acquisition phase has a limited overall impact. LUCs contribute to a negligible impact in all impact categories except for climate change and photochemical ozone formation. Compared to PET cups, the current PLA cups offer environmental impact savings for climate change even including the impacts of LUC. Compared to both PET and PP cups, PLA cups offer savings for fossil fuels resource use but lead to higher impacts for photochemical ozone formation, acidification and terrestrial eutrophication.