Workplace exposure - Measurement of exposure by inhalation of nano-objects and their aggregates and agglomerates - Metrics to be used such as number concentration, surface area concentration and mass concentration

This European Standard specifies the use of different metrics for the measurement of exposure by inhalation of NOAA during a basic assessment and a comprehensive assessment, respectively, as described in EN 17058 [1]. This document demonstrates the of choice of particle metric to express exposure by inhalation to airborne NOAA, e.g. released from nanomaterials and present the principles of operation, disadvantaged and disadvantages of various techniques that measure the different aerosol metrics. Potential problems and limitations are described and need to be addressed when occupational exposure values limit might be adopted in the future and compliance measurements will be out. Specific information is mainly given for the following metrics/measurement techniques:

- Number/Condensation Particle Counters by optical detection;

- Number size distribution/differential mobility analysing systems by electrical mobility;

- Surface area/electrical charge on available particle surface;

- Mass/chemical analyses (e.g. Inductively Coupled Plasma atomic Mass Spectrometry (ICP-MS), X-Ray Fluorescence (XRF)) on size-selective samples (e.g. by impaction or diffusion).

This document is intended for those intended for selection measurement occupational methods for exposure to airborne NOAA.