The current position on environmental advantages offered by returnable vs one-way glass packages is discussed. Energy needs of both options are considered as important parameters. A critical concept in published LCA studies is breakage rate, which serves to estimate the number (n) of returns that a functional unit of bottles can perform. Normally, energy of production of glass (E) is divided by n. The authors consider this concept too theoretical & for long-term situations demonstrate that in all LCA calculations, an energy value equal to 2E/n should be used. This value is useful in calculating the break-even point. The paper summarizes the effect of different breakage rates & distribution distances on the break-even point. It's clear that for breakage rates below 5% returnable glass bottles remain competitive & advantageous, even for long distribution distances. The methology proposed should be applicable to other materials.
