This report assesses different metrics of the concentration of nano (ultrafine) particles in existing and new industries. It describes work carried out in order to determine which metric for very small particles best relates the exposure measurement to the health risk posed by them.
An experimental rig was constructed in which it was possible to expose three instruments, simultaneously, to aerosols generated in a range of concentrations. These aerosols contained ultrafine particles of different chemical composition and particle shape. The relationships between the mass, number and active surface area of these particles, and how they are affected by characteristics such as chemical composition and morphology for these instruments were investigated.- RR513