A Comparative Life Cycle Analysis of The Modern Milkman’s Reusable Glass Milk Bottle

Abstract

The life cycle analysis (LCA) of The Modern Milkman’s reusable glass bottles is compared against the life cycles of high-density polyethylene (HDPE) bottles and beverage cartons, to decide which packaging material had a higher carbon footprint. This shorthand LCA gives an indication on the carbon impact, taking into consideration manufacture, processing, distribution, cleaning, and EoL scenarios. This research is done on the behalf of The Modern Milkman, a company delivering milk and other fast moving consumer goods to customers around the UK.

This thesis concludes that reusable glass bottles is proven to be less carbon impactful compared to HDPE bottles and beverage cartons at a present return rate of 81%. Manufacturing is the most impactful stage of the supply chain for all packaging materials. Cleaning and distribution is an added impact for reusable glass bottles. Regarding the end-of-life scenarios of packaging, recycling of single-use alternatives is possible, yet implications with the UK recycling infrastructure is a barrier. In truth, it is ambiguous if the UKs waste is being managed properly, with much of it being sent abroad.

A breakeven point is calculated, which defines the number of times the reusable glass bottle should be used to have comparable environmental impacts as the single-use alternative. Here, the reusable bottle has to be reused 1.7 times compared to 1L HDPE bottles, and 2.0 times compared to 1L beverage cartons. When the return rate of the glass bottles increases, the number of use cycles increases, causing the production emissions to be spread over a longer lifecycle of the bottle. When the volume of single-use bottles increases, the total carbon footprint decreases and when the recycled content of the HDPE and glass bottles increases, the carbon footprint decreases.