Workplace exposure - Measurement of dustiness of bulk materials containing or releasing respirable nano-objects, their aggregates and agglomerates NOAA or other respirable particles - Part 2: Rotary drum method

This document specifies the methodology for measuring under standard and reproducible conditions the dustiness of bulk materials containing or releasing respirable nano-objects, their aggregates and NOAA agglomerates, or other respirable particles using the rotary drum method. This document specifies the selection of instruments and devices as well as the procedures for calculating and presenting the results. It also provides guidance on data evaluation and reporting. The methodology described in this document enables: a) measurement of the dustiness mass index for the respirable, thoracic and inhalable fractions, b) measurement of the dustiness index for particles in the size range from about 10 nm to about 1 μm, which are part of the respirable fraction, c) measurement of the numerical emission factor for particles in the size range from about 10 nm to about 1 μm, which are part of the respirable fraction, d) measurement of the dimensional distribution of particles released from the material in the size range from about 10 nm to about 10 μm and e) collection of released particles of the respirable fraction for later observation and analysis by electron microscopy. NOTE 1 The particle size range described above is determined on the equipment used in pre-normative tests [4]. This document is applicable to a wide range of bulk materials, including powders, granules or pellets containing or releasing respirable nanoparticles, NOAA aggregates and agglomerates or other respirable particles in unbound, bound, uncoated and coated form. NOTE 2 Currently no dust classification system has been established for the dustiness index or the emission factor. The ultimate intention is to revise this document and introduce a dust classification system as soon as a sufficiently large amount of measurement data is obtained. NOTE 3 The method described in this document has not been tested for dusting numerical factors and particle emission factors for nanofiber and nanoplate materials. However, there is no reason to believe that the numerical dustiness rates or emission factors could not be measured using the rotating drum method using the system described herein. The ultimate intention is to revise this document and introduce a dust classification system as soon as a sufficiently large amount of measurement data is obtained. NOTE 3 The method described in this document has not been tested for dusting numerical factors and particle emission factors for nanofiber and nanoplate materials. However, there is no reason to believe that the numerical dustiness rates or emission factors could not be measured using the rotating drum method using the system described herein. The ultimate intention is to revise this document and introduce a dust classification system as soon as a sufficiently large amount of measurement data is obtained. NOTE 3 The method described in this document has not been tested for dusting numerical factors and particle emission factors for nanofiber and nanoplate materials. However, there is no reason to believe that the numerical dustiness rates or emission factors could not be measured using the rotating drum method using the system described herein. NOTE 3 The method described in this document has not been tested for dusting numerical factors and particle emission factors for nanofiber and nanoplate materials. However, there is no reason to believe that the numerical dustiness rates or emission factors could not be measured using the rotating drum method using the system described herein. NOTE 3 The method described in this document has not been tested for dusting numerical factors and particle emission factors for nanofiber and nanoplate materials. However, there is no reason to believe that the numerical dustiness rates or emission factors could not be measured using the rotating drum method using the system described herein.