On November 15, 2021, the European Union (EU) Observatory for Nanomaterials (EUON) announced the release of a report that it commissioned entitled “Study on the Product Lifecycles, Waste Recycling and the Circular Economy for Nanomaterials.” The study updates and expands on the 2016 Organization for Economic Cooperation and Development (OECD) document entitled “Nanomaterials in Waste Streams — Current Knowledge on Risks and Impacts.” The report covers waste streams containing nanomaterials; behavior and fate of nanomaterials in waste processes; exposure of waste management workers to nanomaterials; benefits and challenges of nanomaterials posed to the circular economy; impact of nanomaterials on recycling; main streams of nanomaterial recyclates; recycling abatement systems residues; potential for substitution of hazardous substances by nanomaterials in the recyclate streams; emission of nanomaterials; and emission control and best available techniques. The review covered 276 publications, including books, research reports, research and review papers, databases, and other Internet resources. The study specifically focuses on manufactured nanomaterials and incidental nanomaterials and on the EU situation and developments in nanomaterials, although researchers reviewed relevant studies from other countries where appropriate. The report includes the following nine conclusions and four recommendations:

• Conclusion 1. Currently, it is not possible to give a sound evidence-based conclusion about the quantities of nanomaterials on the European market and in waste streams.

• Conclusion 2. Public information about nanomaterials is important to waste managers, scientists, regulatory bodies, and consumers.

  • Recommendation 1. The development of public data sets containing information about nanomaterials and their presence in products should be promoted for practical and regulatory decision-making and the advancement of scientific research.

• Conclusion 3. Research on behavior and fate of nanomaterials focuses on relevant nanomaterials in certain waste management facilities and is mostly conducted in a laboratory setting.

• Conclusion 4. Generic mass flow models or fate models have been widely used to provide a general overview of the distribution of specific nanomaterials in the environment.

• Conclusion 5. Substantial progress has been made in developing analytical tools for the characterization and measurement of nanomaterials.

  • Recommendation 2. Predictions from statistical model calculations should be compared to field-scale experiments to assess the quality of the predictions.

• Conclusion 6. No studies about workers’ exposure to nanomaterials in waste management facilities were identified; existing studies focusing on manufacturing and research sites indicate exposure to nanomaterials through inhalation during manual activities, however.

  • Recommendation 3. Field research on the exposure to manufactured and incidental nanomaterials in waste management and recycling facilities should be performed.

• Conclusion 7. The available research shows the high efficiency of incineration and wastewater treatment (for titanium dioxide, zinc oxide, cerium oxide, silver, gold, aluminum, cerium, cobalt, copper, iron, titanium, zinc, and manganese) in limiting emissions of nanomaterials to the environment.

• Conclusion 8. Management of nanomaterials in waste is prescribed by general regulatory provisions, and nano-specific guidance is emerging.

• Conclusion 9. Several potential contributions of nanomaterials to the circular economy were outlined in research publications; there is no evidence of circularity, economic feasibility, or environmental safety of the proposed applications, however.

  • Recommendation 4. The systematization of current research and evaluation of the economic, environmental, and social impact of the proposed applications of nanomaterials in the circular economy should be supported. Closer collaboration and exchange of ideas between researchers and industry is necessary to agree on the needs for nanotechnology solutions and launch appropriate research initiatives.