Life Cycle Inventory of HDPE Bottle-Based Liquid Milk Packaging Systems

This study aims at providing a relatively straightforward methodology to serve as a decision-making tool when more than one packaging solution could be available to a user. It involves a life cycle inventory (LCI) analysis and comparison of three currently available 3.79 l (1 gallon) packaging systems for liquid milk. Two of the primary container types studied use reusable plastic crates (RPCs) for stacking and shipping, while the third type is a heavier duty container that does not require secondary shipping containers. The three primary containers studied are identified as original, cube and stackable throughout this paper. The study shows that the use of RPCs for controlled environment distribution reduces the material requirements of the primary containers and therefore reduces the overall CO2 emissions. It was also found that though the transportation-related emissions varied between the packaging systems for the two end-of-life scenarios considered, it had the lowest overall effect on the CO2 emissions and use of energy. The study concludes that transportation weight limits must be considered as a limiting factor in package design for liquid products, as trailers ‘weigh out’ before they ‘cube out.’ As related to the LCI impacts, this study found that the original and cube container-based packaging systems have better overall per functional unit performance in comparison with the stackable design. It was also noted that scorecards based on the Wal-Mart format do not accurately define the environmental impacts posed by packaging systems.