Multi-indicators environmental impact analysis of takeaway lunch boxes based on life cycle assessment

Conventional plastic take-out food containers exert a substantial environmental impact, necessitating the identification of viable alternatives. A quantitative study assessed the environmental traits of five takeaway lunch boxes made from distinct materials (PP, PE-coated paper, pulp molding, aluminum foil, PLA). A life cycle assessment from 'cradle to grave' was conducted on the evaluation object. Combined with a carbon footprint scenario analysis, this study quantitatively compared and analyzed the environmental impacts of traditional plastic takeaway lunch boxes and their substitutes, spanning from raw material preparation to post-use disposal(including both landfill and recycling). Sensitivity analysis of the study data revealed that the production process significantly influences the environmental footprint of each assessed item. Among the five types of lunch boxes, the PE-coated paper lunch box had the lowest environmental impact, while the pulp-molded lunch box showed the least carbon emissions. Conversely, the PLA lunch box emitted higher carbon emissions than the conventional PP lunch box. Scenario analysis, using a 1250 ml lunch box as the functional unit, indicated that substituting the PP box with PE-coated paper or pulp-molded boxes could reduce the annual carbon footprint of Chinese take-out boxes by 43.20% and 54.35%, respectively. A material substitution ratio of 20:3:1:1 for PE-coated paper, pulp molding, PP, and PLA resulted in a 39.16% reduction in the lunch box's annual carbon footprint. Full recycling of lunch boxes could cut carbon emissions from PE-coated paper boxes by 54%. Implementing a synergistic material replacement scheme and complete recycling could further reduce the carbon footprint by 68.15%.