Today plastic is the most used material for food packaging, but its incorrect disposal is creating environmental issues to oceans, soil and air. Someone believes that the solution is to ban plastic and substitute it with glass packaging. Is it the right choice? This study aims at comparing the environmental impact of bottles made of PET, R-PET, non-returnable glass and returnable glass in order to understand which is the most environmental friendly packaging solution. A literature analysis on the environmental impact of glass and PET bottles is carried out, taking into account their production, transport and disposal phase. Then, an environmental assessment of PET, R-PET, glass and returnable glass bottles, used to package 1 l of pasteurized milk, has been carried out using the life cycle assessment methodology and a new indicator. Inventory data were provided by an important milk processing and packaging factory located in Italy. Results were estimated using some relevant impact categories of the ReCiPe 2016 MidPoint (H) method, then a marine litter indicator (MLI) has been proposed in order to evaluate the polluting potential of milk bottles dispersed into the Mediterranean Sea. LCA results show that R-PET bottle gives the lowest contribution to global warming, stratospheric ozone depletion, terrestrial acidification, fossil resource scarcity, water consumption and human carcinogenic toxicity, followed by PET bottle, returnable glass bottle, and finally non-returnable glass bottle. Glass is the worst packaging option because of high energy demand in the bottle production and its weight and in the transport phase. Some improvements can be obtained with returnable glass, but even if we consider that a bottle could be reused eight times, results are not comparable to the PET or R-PET bottles used only once. However, according to the MLI, returnable glass bottles become the first option, because a lot of plastic bottles could potentially be dispersed into the sea. The substitution of plastic with glass does not help to reduce the GWP and others LCI categories, while could contribute to reduce the marine litter: overall it is important to dispose correctly packaging materials, investing in recycling and reusing. In particular, great improvements can be obtained using bottles made with recycled materials, as R-PET. In conclusion, it is necessary to disadvantage waste dispersion, giving incentives to returnable packaging and raising people awareness of environmental problems.

中文翻译：

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塑料或玻璃：用于比较巴氏杀菌奶瓶的带有海洋垃圾指示器的新环境评估

如今，塑料是食品包装中最常用的材料，但其不正确的处置正在对海洋、土壤和空气造成环境问题。有人认为，解决方案是禁用塑料并用玻璃包装替代。这是正确的选择吗？本研究旨在比较由 PET、R-PET、不可回收玻璃和可回收玻璃制成的瓶子对环境的影响，以了解哪种包装解决方案最环保。对玻璃和 PET 瓶的环境影响进行了文献分析，同时考虑了它们的生产、运输和处置阶段。然后，使用生命周期评估方法和新指标对用于包装 1 升巴氏杀菌奶的 PET、R-PET、玻璃瓶和可回收玻璃瓶进行了环境评估。库存数据由位于意大利的一家重要的牛奶加工和包装工厂提供。使用 ReCiPe 2016 MidPoint (H) 方法的一些相关影响类别估计结果，然后提出了海洋垃圾指标 (MLI)，以评估分散到地中海的奶瓶的污染潜力。LCA 结果表明，R-PET 瓶对全球变暖、平流层臭氧消耗、地球酸化、化石资源稀缺、水消耗和人类致癌毒性的贡献最低，其次是 PET 瓶、可回收玻璃瓶，最后是不可回收玻璃瓶. 玻璃是最糟糕的包装选择，因为瓶子生产及其重量和运输阶段的能源需求很高。使用可回收玻璃可以获得一些改进，但即使我们考虑到一个瓶子可以重复使用八次，结果也无法与只使用一次的 PET 或 R-PET 瓶相比。然而，根据 MLI 的说法，可回收玻璃瓶成为首选，因为大量塑料瓶可能会散布到海中。用玻璃替代塑料无助于降低 GWP 和其他 LCI 类别，但可能有助于减少海洋垃圾：总体而言，正确处理包装材料、投资回收和再利用非常重要。特别是，使用由回收材料制成的瓶子，如 R-PET，可以获得很大的改进。总而言之，有必要减少废物分散、鼓励可回收包装并提高人们对环境问题的认识。