NIOSH requests information on engineered nanomaterials to evaluate the possible adverse health risks of occupational exposure to ENMs. The agency intends to develop categorical occupational exposure limits for ENMs based on the available scientific data regarding the hazard or safety of these materials. NIOSH seeks data on the physicochemical characterization of ENMs; the biological mechanisms and toxicological effects of ENMs; and the dose-response relationships between exposure to ENMs and the development of adverse lung effects such as inflammation, fibrosis, or neoplasia. The agency also requests human, animal, and cellular toxicology data. NIOSH encourages stakeholders to submit relevant information by Feb. 18, 2020. The agency asks that supporting information for published studies include a full citation. For unpublished studies, NIOSH requests that commenters include authors, affiliations, year, and context on how the data were collected. Further details are available in the Federal Register.