There is an increasing interest in reusable bottles as an alternative to single-use packaging from the perspective of assumed reduced littering, waste generation and environmental impacts. In the assessment of a possible shift from single use to reusable bottles, it is important to apply a systems perspective to avoid potential trade-offs between various impacts. Life cycle assessment (LCA) is commonly applied to assess the life cycle impacts of products, typically including the processes of raw material extraction, production, use phase as well as waste management of the products assessed. The goal of this study is to review LCAs of reuse systems for bottles as well as the current European practice in such reuse systems. A recent review of LCAs of reuse systems was applied as the point of departure and complemented by recently published LCA studies. The focus of the review was on methodological aspects and on empirical data for trip rates, i.e., the number of times that the bottle is used during its lifetime. In total, nine LCAs of reuse systems and four European reuse system actors were included in the review as well as some additional highly relevant reports on trip rates.
Several aspects were highlighted as important in the reviewed LCAs of reuse systems. These include the size and composition of beverage packaging, trip rate, transportation distance between retailers and manufacturers, as well as the modelling of end of life of packaging materials, including collection rates. It is important that all these aspects are considered, that the data applied for the compared systems are selected, and that the interpretation of the study results are made, in line with the study goal, which can be to e.g. to compare current or potential future reuse and recycling systems. For example, the collection rate of the packaging in the systems assessed, in turn affected by the type of collection system in place, is one important and sensitive parameter both for single-use and reusable beverage packaging. The reason for this is that the collection rate affects the recycling rate, trip rate and littering rate in the respective single-use and reuse systems. However, detailed discussions on various collection systems, their varying collection rates, or potentials for improving these systems are rarely provided in the reviewed studies. When different collection systems are applied for the compared reuse and single-use bottle systems (e.g. a deposit for reusable bottlesand a voluntary system for single-use bottles), different collection rates will typically occur. A direct comparison of the environmental impact for such systems might therefore be misleading unless the difference in collection rates between the systems are described and in line with the study goal. If the goal of a study is to compare potential future bottle systems, the collection systems applied should be carefully selected to ensure a comparison focusing on differences between the bottle systems (e.g. single-use bottles which are collected for material recycling and converted to raw material for new bottles, or reusable bottles which are collected for refilling), rather than on differences reflecting the underlying collection systems. This is especially important when there are no clear arguments for why the selected collection systems should be different for the bottle systems assessed. However, if the goal is to compare the impact of existing bottle systems, the collection systems applied for the respective bottle systems should be used. Nevertheless, important aspects, such as the collection systems applied for the compared systems, their related collection rates as well as their impact on the results should be acknowledged.
Other important aspects such as social and economic ones were also identified in the reviewed studies. Littering, which commonly is highlighted as an issue related to single-use plastic products, were only assessed in one of the reviewed studies. This literature review is non-exhaustive but provides an overview of recently published LCAs of reuse systems for bottles. The results from this study can provide recommendations to LCA practitioners in conducting future LCAs of reuse systems for bottles to be compared to single-used bottles, as well as to beverage packaging actors, such as reuse system actors.
