The National Institute for Occupational Safety and Health (NIOSH) published a Federal Register notice on December 17, 2019, requesting information on toxicological and physicochemical data of engineered nanomaterials (ENM) to evaluate in developing categorical occupational exposure limits (OEL). 84 Fed. Reg. 68935. As reported in our December 16, 2019, blog item, NIOSH intends to develop categorical OELs based on the available scientific evidence regarding the hazard or safety of ENMs. NIOSH seeks to obtain information, including published and unpublished reports and research findings, to evaluate the possible adverse health risks of occupational exposure to ENMs. Information is due by February 18, 2020. NIOSH will publish a Technical Report that describes the data, methods, and findings for the development of categorical OELs for ENMs, which may include relevant information submitted in response to this request. NIOSH will make the draft Technical Report available for public comment in a subsequent Federal Register notice.