1 Scope
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a) the measurement of the respirable dustiness mass fraction,
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b) the measurement of the number-based dustiness index of respirable particles in the particle size range from about 10 nm to about 1 µm,
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c) the measurement of the initial number-based emission rate and the time to reach 50 % of the total particle number released during testing,
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d) the measurement of the number-based particle size distribution of the released aerosol in the particle size range from about 10 nm to about 10 µm,
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e) the collection of released airborne particles in the respirable dustiness mass fraction for subsequent observations and analysis by analytical electron microscopy.
NOTE 1 The particle size range described above is based on the equipment used during the pre-normative research [8].
NOTE 2 Currently no number-based classification scheme in terms of particle number and emission rate has been established for powder dustiness. Eventually, when a large number of measurement data has been obtained, the intention is to revise the document and to introduce such a classification scheme, if applicable.
NOTE 3 The small rotating drum method has been applied to test the dustiness of a range of materials including nanoparticle oxides, nanoflakes, organoclays, clays, carbon black, graphite, carbon nanotubes, organic pigments, and pharmaceutical active ingredients. The method has thereby been proven to enable testing of a many different materials that can contain nanomaterials as the main component.