Assessment methods for nanoparticles in the workplace.
Proceedings of the Interagency Workshop on the Environmental Implications of Nanotechnology, September 5-7. 2007, Washington, DC. Washington, DC: Environmental Protection Agency, 2007 Sep; :28, 133-139
A typical industrial hygiene analysis of workplace dust exposure does not include instrumentation to detect particles in the nanometer size range. The objectives of the research project were to: (1) identify and evaluate methods to measure airborne nanoparticle concentrations; (2) characterize nanoparticles to assess their surface and bulk physical and chemical properties; and (3) determine the collection efficiencies of commonly used respirator filters when challenged with nanoparticles. The researchers compared a surface area analyzer, handheld condensation particle counter (CPC), photometer, electrostatic precipitator, scanning mobility particle sizer, and an optical particle counter (OPC). They analyzed Fe oxides at high and medium concentrations; TiO2 at high, medium, and low concentrations; and carbon nanotubes. The results indicate a need to apply a shape factor to make direct correlations between instruments, especially when comparing among instruments with different units, such as count, surface area, or mass concentrations. This information will be useful for comparing results obtained by different instruments and for choosing an appropriate instrument for evaluation of nanoparticles in the workplace. In field sampling at a nanostructured lithium titanate facility, the researchers found that material handling of lithium titanate dispersed this material as large particles (> 1 um); any nano-sized particles observed were mainly associated with other sources, such as diesel forklifts and welding and grinding operations.
Nanotechnology; Sampling-methods; Respirable-dust; Dust-measurement; Airborne-dusts; Testing-equipment; Measurement-equipment; Aerosols; Air-samples; Particle-aerodynamics; Particle-counters; Particulate-dust; Analytical-instruments; Analytical-methods; Analytical-processes
Proceedings of the Interagency Workshop on the Environmental Implications of Nanotechnology, September 5-7. 2007, Washington, DC
University of Iowa