On June 28, 2022, the European Union (EU) Observatory for Nanomaterials (EUON) published a Nanopinion entitled “Models to Characterize Exposures to Manufactured Nanomaterials in OECD” by Vladimir Murashov, Ph.D., Senior Scientist in the Office of the Director, National Institute for Occupational Safety and Health (NIOSH), and John Howard, M.D., Director of NIOSH and Administrator of the World Trade Center Health Program in the U.S. Department of Health and Human Services. The authors describe recently completed international projects conducted under the umbrella of the Organization for Economic Cooperation and Development (OECD). Created in 2007 and led by NIOSH, the OECD Steering Group on Exposure Measurement and Mitigation of Nanomaterials (SG8) addresses the exposure component of the risk assessment and risk management program for manufactured nanomaterials. As reported in our November 23, 2022, blog item, on December 2, 2021, the SG8 organized a webinar to present four recent publications on models to characterize exposures to manufactured nanomaterials in workers, consumers, and the environment.

According to the authors, while the results of these SG8 projects “can help guide private and public sector risk assessment and risk management professionals to choose adequate models to identify exposure to manufactured nanomaterials,” the following challenges remain:

• There is a paucity of high-quality experimental exposure data and a very limited number of exposure scenarios hindering model performance testing;

• Most existing models tend to overestimate exposure due to the application of the precautionary approach in the absence of sufficient data; and

• Existing models do not account for agglomeration and aggregation of nanomaterials.

SG8 plans to continue its activities, building on the outputs of exposure model projects and providing further authoritative guidance on the use of exposure models for specific exposure situations. The authors state that for its part, “NIOSH supports international activities aimed at improving safety and health of workers handling manufactured nanomaterials and nano-enabled products.”