RESEARCH PAPER Exposure assessment and engineering control strategies for airborne nanoparticles: an application to emissions from nanocomposite compounding processes Candace S.-J. Tsai • David White • Henoc Rodriguez • Christian E. Munoz • Cheng-Yu Huang • Chuen-Jinn Tsai • Carol Barry • Michael J. Ellenbecker Received: 6 December 2011 / Accepted: 11 June 2012 / Published online: 1 July 2012 Ó Springer Science+Business Media B.V. 2012 Abstract In this study, nanoalumina and nanoclay particles were compounded separately with ethylene vinyl acetate (EVA) polymer to produce nanocom- posites using a twin-screw extruder to investigate exposure and effective controls. Nanoparticle expo- sures from compounding processes were elevated under some circumstances and were affected by many factors including inadequate ventilation, surrounding air flow, feeder type, feeding method, and nanoparticle type. Engineering controls such as improved ventila- tion and enclosure of releasing sources were applied to the process equipment to evaluate the effectiveness of control. The nanoparticle loading device was modified by installing a ventilated enclosure surrounding the loading chamber. Exposures were studied using designed controls for comparison which include three scenarios: (1) no isolation; (2) enclosed sources; and (3) enclosed sources and improved ventilation. Parti- cle number concentrations for diameters from 5 to 20,000 nm measured by the Fast Mobility Particle Sizer and aerodynamic particle sizer were studied. Aerosol particles were sampled on transmission electron microscope grids to characterize particle composition and morphology. Measurements and samples were taken at the near- and far-field areas relative to releasing sources. Airborne particle con- centrations were reduced significantly when using the feeder enclosure, and the concentrations were below the baseline when two sources were enclosed, and the ventilation was improved when using either nanoalu- mina or nanoclay as fillers. Keywords Airborne nanoparticle  Nanoalumina  Nanoclay  Nanocomposite compounding  Inhalation exposure  Engineering control Introduction A nanocomposite is defined as a composite material in which the reinforcing agents are nanoparticles. Nano- composites have the potential to be implemented as new high-strength replacements for traditional Electronic supplementary material The online version of this article (doi:10.1007/s11051-012-0989-z) contains supplementary material, which is available to authorized users. C. S.-J. Tsai (&)  M. J. Ellenbecker NSF Center for High-rate Nanomanufacturing (CHN), University of Massachusetts Lowell, One University Avenue, Lowell, MA 01854, USA e-mail: candace.umass@gmail.com D. White  C. Barry Department of Plastics Engineering, University of Massachusetts Lowell, Lowell, MA, USA H. Rodriguez  C. E. Munoz Industrial Microbiology Department, University of Puerto Rico Mayagu ¨ez, Mayagu ¨ez, Puerto Rico C.-Y. Huang  C.-J. Tsai Institute of Environmental Engineering, National Chiao Tung University, Hsinchu, Taiwan 123 J Nanopart Res (2012) 14:989 DOI 10.1007/s11051-012-0989-z