On July 13, 2021, the National Institute for Occupational Safety and Health (NIOSH) announced the availability of a draft technical report entitled Approaches to Developing Occupational Exposure Limits or Bands for Engineered Nanomaterials: User Guide and Technical Report. 86 Fed. Reg. 36748. NIOSH states that the draft report describes an evidence-based approach to evaluate the scientific information available to derive occupational exposure limits, or bands, for engineered nanomaterials. This draft report contains two main parts: (1) user guide; and (2) full technical report and appendixes. NIOSH seeks comments from individuals, including scientists and representatives from various government agencies, industry, labor, and other stakeholders, and also the public. NIOSH asks that comments note whether there are errors of fact, unsubstantiated claims, evidence of careless experimental work, inclusion of too much information already in the literature, or statements that are inaccurate. NIOSH requests that special emphasis be placed on technical review of the following issues:

• Does the draft document adequately describe the process for gathering and evaluating the information available on occupational exposure limits or bands for engineered nanomaterials?

• Does the draft document adequately describe the development of a framework for categorizing engineered nanomaterials by potential occupational health hazard from inhalation exposure?

• Are the clustering and classification modeling methodologies reasonable for these data?

• Is a revision to current occupational exposure banding guidance needed to incorporate a band F?

• How useful and practical is the approach described in both the user guide and full technical report for deriving categorical occupational exposure limits, and what are the opportunities for improvement?

• Are the current searches and collection of scientific data sufficient, and are there additional opportunities for obtaining data that were not included?

• Would the methods used in the report also be appropriate for a future comprehensive dataset of experimental, toxicological, and physicochemical information for engineered nanomaterials?

Comments are due September 13, 2021.