NORA Manufacturing Sector Strategic Goals
921Z6KS - Dustiness of NanomaterialsStart Date: 10/1/2006
End Date: 9/30/2009
Principal Investigator (PI)Organization: NIOSH
Funded By: NIOSH
Primary Goal Addressed5.0
Secondary Goal Addressed9.0
Attributed to Manufacturing
There is growing concern that the accelerated growth in the nanotechnologies will expose a large population of workers to potentially hazardous nanoscale materials. The unique physical properties that make these materials of commercial interest may also make them potentially more hazardous. In line with goals in Manufacturing and Nanotechnology, the proposed research will identify those nanomaterials that are most prone to aerosolization (i.e. dusty) in workplaces, which in turn may pose either an inhalation or safety hazard. Identification will allow health and safety professionals, industry and other stakeholders to target their control efforts towards those nanomaterials which may pose the greatest risks. Quantitative dustiness data from this research will provide the basis for control banding of nanomaterials.
In prior pilot research guided by the PI, a newly developed dustiness tester originally intended for use within the pharmaceutical industry has, with minor modifications, been utilized for nanomaterial dustiness testing. Dustiness of powdered materials is a measure of the propensity of a material to aerosolize; and the equivalent for powdered-solids, as vapor pressure is to volatile liquids. The described tester allows small (mg) quantities of materials to be tested in a fully enclosed and repeatable manner, both important assets for cost prohibitive or pre-production samples or with hazardous/presumed hazardous materials. In addition to further developing testing protocols and methods, approximately ten fine and nanostructured materials have been evaluated, (with replicates), according to total and respirable mass at three humidity regimes (low, medium and high). The proposed research extends previous pilot work to test a broader range of materials and provides for more extensive measurements of dispersed materials. Proposed measurements will include particle mass, surface area and number, together with particle size distribution measurements of the dispersed fraction. A second dispersion chamber with further modifications will be constructed to allow size distribution measurements to be properly performed. The proposed laboratory research will take place during FY09. Report writing and journal publication will take place thereafter.
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Many nanomaterials are currently being produced as part of the burgeoning interest in nanotechnology. The manufacturing, processing and handling of nanomaterial powders presents a real risk to release of aerosolized material. It has been estimated that an additional two million workers will be required globally to support the rapid growth in the nanotechnologies by 2015, with one million of these based in the United States. Recent, in-vivo and in-vitro studies have demonstrated that a number of these nanomaterials may be hazardous to human health and the high specific surface area of these materials may also enhance the reactivity, fire or explosion risk, if uncontrolled airborne dispersion occurs. Recent research has also demonstrated a strong correlation between a material's dustiness (propensity of material to become airborne) and workers' exposure during handling of fine powders. Dustiness testing is designed to simulate the mechanisms of particle release from powdered materials by common work practices. Dustiness testing of nanomaterials may therefore provide a prudent approach to identifying materials which pose an enhanced worker inhalation or safety hazard, aid in identifying processes likely to cause airborne release, and where targeted control measures need to be implemented.
The proposed research compliments detailed workplace measurements within nanoscale workplaces on process/task emissions and exposure assessments that have been completed, are currently in progress, or are planned by the PI and other key NIOSH personnel on this proposal. The proposed work also compliments external work conducted in conjunction by our partners and collaborators at the UK Health and Safety Laboratory on the dustiness testing of similar nanoscale materials. The proposed research will advance goals for the Manufacturing Sector and the Respiratory Diseases and Exposure Assessment cross sectors by both identifying and providing a better understanding of materials which may pose either an inhalation exposure and/or safety hazard. Specifically, the project addresses intermediate goal (IG) 2.11 of the Exposure Assessment cross sector: Address critical exposure assessment needs in emerging areas such as nanotechnology and activity/output 2.11.1 in the development of exposure assessment tools to characterize and evaluate the exposure to these emerging areas. The project further supports or provides input to six of the ten critical research topics within the Nanotechnology Research Center and the Nanotechnology cross-sector and specifically supports IG 1.1 and 7.1: Determine key factors influencing the generation, dispersion, deposition and re-entrainment of nanomaterials in the workplace, including mixed exposures; identify physical and chemical properties that contribute to dustiness, combustibility, flammability and conductivity of nanomaterials. The research additionally contributes to the Respiratory Disease IG 5.2: to characterize respiratory exposures and measures used to reduce exposures, including engineering controls and respiratory protection in work settings where engineered nanomaterials are produced or used. The research further supports the Cancer, Reproductive and Cardiovascular Diseases cross sector IG 1.1: to conduct research to reduce work-related cancer. Outputs of this project are of global interest and will be shared, for example with our international partners through Global Collaborations.
- Page last reviewed: July 22, 2015
- Page last updated: July 6, 2015
- Content source:
- National Institute for Occupational Safety and Health (NIOSH) Office of the Director