A Content Review of Life Cycle Assessment of Nanomaterials: Current Practices, Challenges, and Future Prospects

This paper provides a comprehensive review of 71 previous studies on the life cycle assessment (LCA) of nanomaterials (NMs) from 2001 to 2020 (19 years). Although various studies have been carried out to assess the efficiency and potential of wastes for nanotechnology, little attention has been paid to conducting a comprehensive analysis related to the environmental performance and hotspot of NMs, based on LCA methodology. Therefore, this paper highlights and discusses LCA methodology's basis (goal and scope definition, system boundary, life cycle inventory, life cycle impact assessment, and interpretation) to insights into current practices, limitations, progress, and challenges of LCA application NMs. We found that there is still a lack of comprehensive LCA study on the environmental impacts of NMs until end-of-life stages, thereby potentially supporting misleading conclusions, in most of the previous studies reviewed. For a comprehensive evaluation of LCA of NMs, we recommend that future studies should: (1) report more detailed and transparent LCI data within NMs LCA studies; (2) consider the environmental impacts and potential risks of NMs within their whole life cycle; (3) adopt a transparent and prudent characterization model; and (4) include toxicity, uncertainty, and sensitivity assessments to analyze the exposure pathways of NMs further. Future recommendations towards improvement and harmonization of methodological for future research directions were discussed and provided. This study's findings redound to future research in the field of LCA NMs specifically, considering that the release of NMs into the environment is yet to be explored due to limited understanding of the mechanisms and pathways involved.

Automated summary

This paper provides a comprehensive review of 71 previous studies on the life cycle assessment of nanomaterials from 2001 to 2020, highlighting the lack of comprehensive LCA studies on the environmental impacts of NMs until end-of-life stages in most previous research. Recommendations for future studies include reporting more detailed and transparent data, considering environmental impacts and potential risks throughout the life cycle of NMs, adopting a transparent characterization model, and conducting toxicity, uncertainty, and sensitivity assessments to analyze exposure pathways further. The findings of this study contribute towards future research on LCA NMs, especially considering the limited understanding of mechanisms and pathways involved in the release of NMs into the environment.