Optimizing the environmental performance of food product package systems: A life cycle assessment of the tradeoff's between packaging design and food waste

CSS Publication Number: 
CSS17-04
Abstract: 

Final project report to the Center for Packaging Innovation and Sustainability

Food waste is a critical contemporary issue, both in the U.S. and internationally, in terms of food security and food system sustainability. Addressing this intricate problem will require multi-faceted approaches from corporate, government and personal fronts. Food packaging is ubiquitous in modern food systems, serving the primary function of protecting and distributing the right product to the right end-user in a safe, cost-efficient and user-friendly way. As a highly engineered and designed interface between food and the end user, food packaging offers an acute lever for influencing food wastage, both by inhibiting physical and bio-chemical degradation of food, but also by “scripting” individual behaviors around food handling, preparation, preservation and disposal. Yet, in the sustainable food packaging conversation to date, very little attention has been given to packaging’s ability to contribute to net reductions in the environmental impact of food life cycles by reducing food waste.

A primary goal of this research project was to demonstrate the use of life cycle assessment in elucidating the environmental trade-offs between food waste and food packaging. A thorough review of the literature (Section 3) grounds this work in a solid academic foundation among food waste, food packaging, and food life cycle assessment. The major deliverable from the project was development of a life cycle assessment model capable of investigating the influence of both food waste and food packaging on the full life cycle environmental impact (focused on the indicators of greenhouse gas emissions (GHGE) and non-renewable energy demand) for specific food products and packaging configurations. This model was first used to map a wide variety of food types and their typical packaging configurations in order to elucidate general principles dictating the environmental trade off between food waste and food packaging (Section 7). Three specific case studies were also developed based on empirical food waste rates at retail in order to explore how changes in packaging effect food waste and full life cycle environmental performance.

The mapping exercise detailed in Section 7 identifies the “food-to-packaging ratio” – defined as the environmental impact (say, GHGE) associated with producing and processing the food divided by the environmental impact of producing packaging materials – as a useful scan-level indicator of the influence that food waste will have on overall system environmental performance. Often, estimates of this ratio can be generated without conducting a full life cycle assessment on a given product, offering a potential tool to assist in packaging design. At high food-to-packaging ratios, food waste is likely to have a strong influence on system environmental performance, and investments (in terms of increased environmental impact) in packaging that result in reduced food waste are likely to lead to net system environmental benefit. On the other hand, very low food-to-packaging ratios (less than unity) indicate that it will be much more difficult for investments in packaging aimed at reducing food waste to lead to net reductions in environmental impact. In these instances, sustainable design efforts are likely better directed at reducing the impact of the packaging itself.

The three case studies documented in this report offer three rather different viewpoints on the food waste/ packaging interaction. The first two cases are parallel in design: both compare bulk distribution and retail of fresh vegetables (with minimal packaging) to vegetables pre-packaged in PET trays/boxes. In both the case of mushrooms (Section 8) and spinach (Section 9), measured retail food waste rates were lower for the pre-packaged product than for the bulk product. With mushrooms, this decrease in food waste led to a net reduction in system GHGE and energy demand, despite the fact that packaging had a larger impact. In the spinach case, however, the food-to-packaging GHGE ratio is much lower (0.27 vs. 6.9 for mushrooms), and reductions in food waste were unable to balance out the increased impact of packaging, resulting in a net increase in GHGE and energy demand when going from bulk to pre-packaged spinach distribution and retailing.

The third case explores the common question of fresh vs. frozen vs. canned fruits and vegetables. Specific packaging is required to allow these preservation techniques to be marketed. The question asked in this case is whether the material and energy investments required for freezing and canning result in a net environmental benefit if retail food waste is taken into account? Pre-packaged, fresh green beans were compared with both frozen and canned green beans; the fresh beans exhibited retail-level waste rates at least a factor of ten higher than frozen or canned. Yet, system GHGE and energy demand were driven largely by processing and retail refrigeration energy requirements, resulting in greater system impacts with frozen and canned beans. Break-even scenarios were considered by assuming the frozen and canned beans also resulted in lower consumer-level food waste. Very low consumer-level waste rates were required for freezing and canning to break-even with the fresh scenario. If the fresh beans were assumed out-of-season and therefore transported a much greater distance, consumer-level waste rates still needed to be decreased in order for the preserved beans to break even, but these reductions were more reasonable. A similar comparison was made between fresh and frozen blueberries. Frozen had lower retail-level waste rates, but GHGE and energy demand were still greater than the fresh scenario. These results are very sensitive to processing energy demand and trends could change with more accurate data.

In conclusion, this project has demonstrated the opportunities, both theoretically and in empirically based case studies, for packaging to contribute to reduced food waste and for such waste reductions to lead to net environmental benefits. The project has also demonstrated, however, that the environmental balance between food waste and food packaging can be delicate, and careful assessment and quality waste rate data are needed in order to demonstrate a net environmental benefit in these tenuous cases. The detailed cases explored in this project lie close to the balancing point, making them interesting case studies. Surely there are other food/packaging combinations where the food-to-packaging ratio is much higher (beef, for instance) and opportunities for food waste reduction to result in system environmental benefit are much more certain. As a fully designed system at the interface between food and the end user, the opportunities for packaging to further influence food waste cannot and should not be overlooked.

Publication Type: 
Report
Date Published: 
March 3, 2017
Full Citation: 
Heller, Martin and Gregory Keoleian. (2017) “Optimizing the environmental performance of food product-package systems: A life cycle assessment of the tradeoffs between packaging design and food waste.” CSS Report, University of Michigan: Ann Arbor 1-87.
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Publication Status: 
Published