Fig. 5: SEM images of the TiO2 NF raw material and the material measured in the emission zone and the personal breathing zone in Study B.

a The raw material of TiO2 NFs used, b TiO2 NFs found on the emission zone filter sampled during work task B5, and c TiO2 NFs found on the personal breathing zone filter sampled during work task B5–6.