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 Manufacturing100%
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.
Subsequent citation in the peer reviewed literature is a good indicator of awareness and acceptance of a particular piece of quality research. Such citation may be easily tracked using for example, Google Scholar. Feedback from stakeholders is also an important method to evaluate how well the outputs of the project have been disseminated.
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.