There is currently a shift from petrochemical to bio-based plastics (bioplastics). The application of comprehensive and appropriately designed LCA studies are imperative to provide clear evidence on the comparative sustainability of bioplastics. This review explores the growing collective of LCA studies that compare the environmental footprints of specific bioplastics against those of petrochemical plastics. 44 relevant studies published between 2011 and 2020 were reviewed to explore important methodological choices regarding impact category selection, inventory completeness (e.g. inclusion of additives), boundary definition (e.g. inclusion of land-use change impacts), representation of biogenic carbon, choice of end-of-life scenarios, type of LCA, and the application of uncertainty analysis. Good practice examples facilitated identification of common gaps and weaknesses in LCA studies applied to benchmark bioplastics against petrochemical plastics. Many studies did not provide a holistic picture of the environmental impacts of bioplastic products, thereby potentially supporting misleading conclusions. For comprehensive evaluation of bioplastic sustainability, we recommend that LCA practitioners: embrace more detailed and transparent reporting of LCI data within plastic LCA studies; adopt a comprehensive impact assessment methodology pertaining to all priority environmental challenges; incorporate multiple plastic use cycles within functional unit definition and system boundaries where plastics can be recycled; include additives in life cycle inventories unless there is clear evidence that they contribute <1% to all impact categories; apply biogenic carbon storage credits only to long-term carbon sinks; account for (indirect) land-use change arising from feedstock cultivation; prospectively consider realistic scenarios of deployment and end-of-life, preferably within a consequential LCA framework.

当前，已经从石化转变为生物基塑料（生物塑料）。必须应用全面和适当设计的LCA研究，以提供有关生物塑料比较可持续性的明确证据。这篇综述探索了越来越多的LCA研究，这些研究比较了特定生物塑料和石化塑料的环境足迹。审查了2011年至2020年之间发表的44篇相关研究，以探讨关于影响类别选择，清单完整性（例如，添加添加剂），边界定义（例如，包括土地用途变化影响），生物碳的代表，最终选择的重要方法选择生活场景，LCA类型以及不确定性分析的应用。优良作法实例有助于识别LCA研究中常见的缺陷和不足之处，这些研究适用于针对石化塑料的基准生物塑料。许多研究没有提供生物塑料产品对环境的整体影响，因此可能支持误导性结论。为了全面评估生物塑料的可持续性，我们建议LCA专业人员：在塑料LCA研究中采用更详细和透明的LCI数据报告；采用与所有优先环境挑战有关的综合影响评估方法；在功能单元定义和可回收塑料的系统范围内纳入多个塑料使用周期；在生命周期清单中包括添加剂，除非有明确证据表明它们有助于 所有影响类别的1％；仅将生物碳储量信用额度应用于长期碳汇；解释因原料种植引起的（间接）土地利用变化；前瞻性地考虑实际的部署和寿命终止方案，最好在相应的LCA框架内。