Engineered nanomaterials exposure in the production of graphene

The study design consisted of the combination of (i) direct-reading instruments, used to evaluate the total particle number concentrations relative to the background concentration (time series with spatial approach) and the mean size-dependent characteristics of particles (mean diameter and surface-area concentration) and (ii) filter-based air sampling for the determination of size-resolved particle mass concentrations.

The data obtained from direct reading measurement were then used to estimate the 8-hour time weighted average (8-hr TWA) exposure to GFNs particles for workers involved in different working tasks. Workers were generally exposed to 8-hr TWA GFNs particle levels lower than the proposed reference value (40000 particle/cm 3 ). Furthermore, despite high short-term exposure conditions were present during specific operations of the production process, the possibility of significant exposure peaks is not likely to be expected.