A novel device for measuring respirable dustiness using low-mass powder samples.
O'Shaughnessy-PT; Kang-M; Ellickson-D
J Occup Environ Hyg 2012 Mar; 9(3):129-139
Respirable dustiness represents the tendency of a powder to generate respirable airborne dust during handling and therefore indicates the propensity for a powder to become an inhalation hazard. The dustiness of 14 powders, including 10 different nanopowders, was evaluated with the use of a novel low-mass dustiness tester designed to minimize the use of the test powder. The aerosol created from 15-mg powder samples falling down a tube were measured with an aerodynamic particle sizer (APS). Particle counts integrated throughout the pulse of aerosol created by the falling powder were used to calculate a respirable dustiness mass fraction (D, mg/kg). An amorphous silicon dioxide nanopowder produced a respirable D of 121.4 mg/kg, which was significantly higher than all other powders (p < 0.001). Many nanopowders produced D values that were not significantly different from large-particle powders, such as Arizona Road Dust and bentonite clay. In general, fibrous nanopowders and powders with primary particles >100 nm are not as dusty as those containing granular, nano-sized primary particles. The method used here, incorporating an APS, represents a deviation from a standard method but resulted in dustiness values comparable to other standard methods.
Nanotechnology; Sampling-methods; Respirable-dust; Risk-analysis; Dust-measurement; Airborne-dusts; Inhalants; Testing-equipment; Measurement-equipment; Aerosols; Air-samples; Particle-aerodynamics; Particle-counters; Particulate-dust; Analytical-instruments; Analytical-methods; Silicon-compounds;
Author Keywords: dustiness; nanoparticle; risk assessment
Patrick O'Shaughnessy, Occupational and Environmental Health, College of Public Health, 100 Oakdale Campus, 137 IREH, Iowa City, IA 52242
Grant-Number-R01-OH-008806; Grant-Number-R01-OH-009448; B03282012
Journal of Occupational and Environmental Hygiene
University of Iowa