title: A novel device for measuring respirable dustiness using low-mass powder samples.
abstract: 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.
authors.affiliation: Occupational and Environmental Health, College of Public Health, The University of Iowa, Iowa City, Iowa 52242, USA. patrickoshaughnessy@uiowa.edu
authors.forename: Patrick T
authors.initials: PT
authors.lastname: O'Shaughnessy
authors.forename: Mitchell
authors.initials: M
authors.lastname: Kang
authors.forename: Daniel
authors.initials: D
authors.lastname: Ellickson
mesh_terms: D004391:Dust / Q000032:analysis*; D004784:Environmental Monitoring / Q000295:instrumentation* / Q000379:methods; D019570:Inhalation Exposure / Q000032:analysis; D053758:Nanoparticles / Q000032:analysis; D016273:Occupational Exposure / Q000032:analysis; D010316:Particle Size
chemical_list: D004391:Dust