Safety opportunities for the synthesis of metal nanoparticles and short-cut approach to workplace risk evaluation

Notwithstanding the extensive use of engineered nanomaterials in various industrial and research settings, the impact of nanotechnology on the environment and its safety implications on the industrial production are still a challenging task. To date, the databases about nano-toxicology have a limited amount of information to establish suitable and widely accepted workplace safety regulations, both in relation with the toxicological/hazardous properties, lifecycle assessment, potential exposure pathways and the actual estimation of the number of workers exposed. Application of nano-materials in the process industries became an everyday practice in the last decade. However, the potential health hazard in producing, processing and using them has not been known exactly, yet. Accordingly, evaluating the hazard and calculating risk in their application leads to safer usage. Additionally, the development of cleaner production routes for nano-materials also contributes to minimizing the risk during their production. This paper introduces a critical discussion on cleaner and inherent safer approaches to the chemical synthesis of metal nanoparticles and outlines two novel synthesis processes for nano bismuth, a semimetal widely exploited in heterogeneous catalysis, microelectronic and thermoelectric applications, magnetic field sensors etc. The methods for Bi nano synthesis, which are inherently much safer, are subsequently analysed by a short-cut tool offering a semi-quantitative estimation of the hazards for workers employed in the given research environment, starting from the concepts borrowed by the layer of protection analysis. Additionally, the screening tool, by comparing the hazardous character of processes, can help choosing the safer, cleaner and more eco-friendly one. (C) 2018 Elsevier Ltd. All rights reserved.