RESUMEN
In early 2006, the National Institute for Occupational Safety and Health created a field research team whose mission is to visit a variety of facilities engaged in the production, handling, or use of engineered nanomaterials (ENMs) and to conduct initial emission and exposure assessments to identify candidate sites for further study. To conduct the assessments, the team developed the Nanoparticle Emission Assessment Technique (NEAT), which has been used at numerous facilities to sample multiple engineered nanomaterials. Data collected at four facilities, which volunteered to serve as test sites, indicate that specific tasks can release ENMs to the workplace atmosphere and that traditional controls such as ventilation can be used to limit exposure. Metrics such as particle number concentration (adjusted for background), airborne mass concentration, and qualitative transmission electron microscopy were used to determine the presence, nature, and magnitude of emissions and whether engineered nanomaterials migrated to the workers' breathing zone. [Supplementary materials are available for this article. Go to the publisher's online edition of Journal of Occupational and Environmental Hygiene for the following free supplemental resource: a PDF file containing information on facilities, a description of processes/tasks, existing controls, and sampling strategy, and a PDF file containing TEM images according to facility and task.].