The National Institute for Occupational Safety and Health conducted an initial, task-based comparative assessment to determine the potential for release of carbon nanofibers (CNFs) during dry material handling, wet cutting, grinding, and sanding (by machine and hand) of plastic composite material containing CNFs. Using a combination of direct-reading instruments and filter-based air sampling methods for airborne mass and transmission electron microscopy (TEM), concentrations were measured and characterized near sources of particle generation, in the breathing zone of the workers, and in the general work area. Tasks such as surface grinding of composite material and manually transferring dry CNFs produced substantial increases in particle number concentration (range = 20,000-490,000 1-cm(-3)). Concomitant increases in mass concentration were also associated with most tasks. Nearly 90% of all samples examined via TEM indicated that releases of CNFs do occur and that the potential for exposure exists. These findings also indicate that improperly designed, maintained, or installed engineering controls may not be completely effective in controlling releases. Unprotected skin exposure to CNFs was noted in two instances and indicated the need for educating workers on the need for personal protective equipment. [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 materials, evaluated processes, personal protective equipment, and existing ventilation/engineering controls.].
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.].
Material safety data sheets (MSDSs) provide employers, employees, emergency responders, and the general public with basic information about the hazards associated with chemicals that are used in the workplace and are a part of every-day commerce. They are a primary information resource used by health, safety, and environmental professionals in communicating the hazards of chemicals and in making risk management decisions. Engineered nanomaterials represent a growing class of materials being manufactured and introduced into multiple business sectors. MSDSs were obtained from a total of 44 manufacturers using Internet search engines, and a simple ranking scheme was developed to evaluate the content of the data sheets. The MSDSs were reviewed using the ranking scheme, and categorized on the quality and completeness of information as it pertains to hazard identification, exposure controls, personal protective equipment (PPE), and toxicological information being communicated about the engineered nanomaterial. The ranking scheme used to evaluate the MSDSs for engineered nanomaterials was based on the determination that the data sheet should include information on specific physical properties, including particle size or particle size distribution, and physical form; specific toxicological and health effects; and protective measures that can be taken to control potential
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