Control of worker exposure during handling of manufactured nanomaterials in fume hoods

Fume hoods are one of the most common methods of controlling exposure in laboratory environments (Balas et al. 2010). In this research the potential release and the workers’ inhalation exposure during synthesis and handling of manufactured nanomaterials (MNMs; CuO, ZnO and TiO2) under a laboratory fume-hood was assessed (Fonseca et al. 2018). In order to increase confidence in worker protection by fume hoods, the capacity of a fume hood to prevent particle release to laboratory air during simulated spillage was also evaluated by varying drop height and mass load (Fonseca et al. 2018). Synthesis, handling and packaging of MNM did not result in detectable particle release to the laboratory air. During simulated spills, notable increase in particle concentrations were rarely detected in the breathing zone of the worker (Figure 1a and b). However, powder spills were sometimes observed to eject into the laboratory room (Figure 1c) and contaminate the workers’ laboratory clothing. In contrast to statements in previous scientific publications, this study confirms that an appropriate fume-hood with an adequate sash height of 0.3-0.5 m and face velocities ranging from 0.1 to 0.4 m s-1 provide high exposure control during synthesis and handling of MNMs. Here, preventing on average 98% of particles release into the surrounding environment. Nevertheless, safe approaches for cleaning powder spills should be prepared to prevent exposure via resuspension and inadvertent exposure by secondary routes.