Exposure to graphene in a pilot production plant

Workers exposure to graphene was measured in a pilot production plant. Reduced graphene oxide was produced through graphite oxidation and posterior thermal reduction. The monitoring was performed using two handheld on-line devices covering the particle size range from 10 nm to 10 mu m (CPC3007 and OPS3330). Simultaneously, personal and area filter samples were collected for off line analysis, including gravimetric, elemental carbon analysis and SEM/EDX. Significant releases of particles were identified in two tasks, during the graphene oxide washing, and during its milling. However, the analysis of the particles size distribution and of their morphology suggested that the released particles were not the target nanomaterial but engine generated nanoparticles. The mass of elemental carbon in the collected filters was below the quantification limit and the calculated graphene mass concentrations were quite below the selected reference exposure limit. Overall, this work showed that worker exposure to graphene was low in this pilot plant, contributing to guarantee a safe process, prior to its industrialization.