Emission into the workplace was measured for the production process of silicon nanoparticles in a pilot-scale facility at the Institute of Energy and Environmental Technology e.V. (IUTA). The silicon nanoparticles were produced in a hot-wall reactor and consisted of primary particles around 60 nm in diameter. We employed real-time aerosol instruments to measure particle number and lungdeposited surface area concentrations and size distribution; airborne particles were also collected for offline electron microscopic analysis. Emission of silicon nanoparticles was not detected during the processes of synthesis, collection, and bagging. This was attributed to the completely closed production system and other safety measures against particle release which will be discussed briefly. Emission of silicon nanoparticles significantly above the detection limit was only observed during the cleaning process when the production system was open and manually cleaned. The majority of the detected particles was in the size range of 100-400 nm and were silicon nanoparticle agglomerates first deposited in the tubing then resuspended during the cleaning process. Appropriate personal protection equipment is recommended for safety protection of the workers during cleaning.
Bibliographical noteFunding Information:
Acknowledgments The work was partially supported by the National Institute of Environmental Health Sciences Grant # 1RC2ES018741-01 (Sub-Grant 100029-D) on ‘‘Hazard Assessment and Risk Estimation of Inhaled Nanomaterials Exposure’’ and by the NSF grant (Award ID: 0646236) on ‘‘Experimental and Numerical Simulation of the Fate of Airborne Nanoparticles from a Leak in a Manufacturing Process to Assess Worker Exposure’’. The emission measurements were performed during the production cycle of silicon nanoparticles at IUTA e.V. The authors thank the production team: Mathias Spree, Stefan Berthold, Christof Jurczyk and Frank Krumpolt for collaboration.
- Emission measurement
- Nanoparticle agglomerates
- Silicon nanoparticles
- Workplace safety