The environmental impacts of reusable rice packaging: An extended comparative life cycle assessment

Abstract

Plastic packaging recycling has gained momentum as it can improve the circularity of this typical linear product. However, reuse ranks as a preferred strategy over recycling because product reuse can reduce material usage compared to product recycling and keeps material value higher for a longer time. Such reusable plastic packaging requires, besides a more robust product design, an additional return system. It is crucial to minimize the impact of this product system and ensure that reusable plastic packaging is not only more circular, but also more environmentally friendly than its single-use alternative. For this purpose, understanding the factors contributing to its environmental impact is key. In this paper, a new design of reusable packaging for two kilogram rice is compared with a conventional fully-optimized single-use packaging using a prospective extended life cycle assessment, including a circularity (using material flow analysis and specific circularity indicators, among which the Material Circularity Index), environmental impact (using a life cycle assessment with 16 midpoint indicators) and packaging-related food losses and waste assessment (using the food-to-packaging ratios). On average, the reusable rice packaging could be reused five times, due to losses at the distribution, use, and reuse preparation phase. While the reusable packaging scores better on the circularity indicators (a Material Circularity Index of 91 %, compared with 39 % for single-use packaging), its global warming and fossil resource depletion impact are respectively two and three times higher, considering a functional unit of one kilogram cooked rice to be consumed. The reusability and return rate, providing the retention of reusable packaging at the reuse preparation and use phase, respectively, were identified as the most determinative parameters by the sensitivity analysis. If these parameters could be optimized to a value of 99.75 %, corresponding to a total of 16 uses, the climate change impact of reusable packaging would be lower than its conventional single-use counterpart. The high food-to-packaging ratios (more than 18 for all impact categories) point to the importance of reducing food waste. If the packaging design could reduce food losses in the product system with 0.2 %, the reusable packaged rice would have a lower water use and mineral and metal resource use impact compared to the single-use packaged rice, despite the higher environmental impact of the reusable packaging unit itself. Therefore, this should be prioritized when further optimizing the reusable packaging design.