Dustiness is the tendency of particles to become or stay airborne. Dustiness is affected by the particle bulk density, shape, size, and inherent electrostatic repulsive forces. Materials in dry powder form are generally more dusty than those in slurries or liquid suspensions, with particles embedded in a sold matrix being the least dusty. Some processes such as sonication increase the airborne concentration of dusty materials. Dustiness increases the risk of inhalation exposure.
Dusty materials tend to generate aerosols with high particle concentrations measured in number or in mass. The tendency of powdered materials to release airborne particles under external energies indicates their dustiness level.
The dusty level of powders directly affects worker exposure scenarios and associated health risks in occupational settings. Powder-based aerosol particles can pose advert effects when deposited in human respiratory systems via inhalation.
Various laboratory systems have been developed to test dustiness of fine powders. A European standard on dustiness testing has been established by the European Committee for Standardization (CEN) since April 2006. This standard is especially related to human exposure in workplace (EN 15051). It describes two methods: the rotating drum system and continuous drop system. Recently, an aerosol generation system based on laboratory funnel (resembling a fluidized bed) has been developed, which has the potential to become an alternative or supplementary method to the existing systems in dustiness testing. Its performance was compared to other three aerosolization systems using the same test materials.