Consideration of Plastic Emissions in Life Cycle Assessments

Life cycle assessment (LCA) is the method most frequently used to systematically assess the environmental impacts of products and services over their entire life cycle. Several environmental impacts, such as global warming or ozone depletion, are covered. Life cycle assessments do not yet allow, however, for considering the consequences of plastic waste leaking into the environment. Thus, plastic products such as PET bottles might appear beneficial (having, for example, a lower carbon footprint than alternatives such as glass bottles) although they contribute to potentially harmful effects if released into the environment. In addition, the absence of an impact assessment method addressing plastic emissions limits the possibility of analyzing the trade-offs between impact categories. In order to provide an overview of the state of the art of plastic emissions in LCA, the chapter begins with an overview of the LCA methodology in general. There follows a description of the potential impact pathways of plastic emissions using a framework developed by the International Working Group MarILCA on Marine Impacts in Life Cycle Assessment. Within the framework, relevant existing impact categories are discussed, and new ones are proposed. The following section describes accounting methods for plastic emissions and ways of defining plastic flows in life cycle inventory (LCI). The already developed approaches addressing plastic emissions in life cycle impact assessment (LCIA) are then described in relation to the framework and, in addition, examples of applications (case studies) are presented. Finally, future research needs are discussed.