Comparing reusable to disposable products: Life cycle analysis metrics

This research is to produce the first quantitative evaluation, using global warming potential (GWP, kg CO₂ eq), of all published cradle-to-gate life cycle studies that compare reusable vs single-use products. We seek to determine whether there are consistent and fundamental factors that differentiate disposable and reusable products. A comparative assessment was made of the cradle-to-gate life cycle analyses of all published comparisons of reusable and single-use products from 1990 to 2016. A literature search found only 20 products in which a full life cycle analysis of cradle-to-gate (supply chain, manufacturing, reprocessing, and packaging of the reusable item) and supply chain plus manufacturing for the disposable had been published. GWP or carbon footprint was used as the environment comparison metric to which we added energy for the product manufacturing metrics. In this diverse set of products, the reusable product was consistently lower in cradle-to-gate energy use and global warming potential than the comparable single-use product. However, no apparent product characteristic appeared to govern the extent by which the reusable had a lower carbon footprint. These compelling results were compared with two other references in which disposable products were reported as better. However, when the data were reviewed with those authors, they reevaluated and found errors in calculations and corrected the results to then identify the lower reusable GWP impact compared to the respective disposable. The diversity of products studied and the consistently lower GWP impact of reusable products herein may suggest that products with reusable/disposable options could be predicted to show that the reusable is better than the single-use option.