SiO₂ Aerosol Nanoparticle Reactor for Occupational Health and Safety Studies

Abstract

Important questions are emerging about potential occupational safety, toxicological, and ecotoxicological effects and occupational inhalation exposure risks to engineered aerosol nanoparticles. Although multiple avenues are available to synthesize nanoparticles, few tools are accessible to industrial hygienists and inhalation toxicologists to produce well-characterized aerosols of known aerosol size distribution and particle number concentration that are stable, simple, and robust to operate. This article describes a SiO ₂ aerosol nanoparticle reactor that has been developed as a tool for the study of the safety, health, and environmental consequences of exposure to nanoparticle synthesis and processing. The SiO ₂ aerosol nanoparticle reactor is capable of stable, long-term synthesis of amorphous SiO ₂ aerosol nanoparticles from d ₅₀ = 10–70 nm at particle concentrations ∼ 10 ⁴ –10 ⁷ particles/cm ³ that does not produce halogen-containing byproducts and does not require daily monitoring of the particle size distribution. This reactor is designed to produce a well-characterized aerosol to enable subsequent testing with a continuous, stable supply of aerosol nanoparticles (i) to facilitate inhalation toxicology studies, (ii) to measure explosion characteristics of aerosol nanoparticles, (iii) to determine the barrier efficacy for respirator filtration, bag house exhaust, and personal protective garment media challenged with diverse aerosol nanoparticles, and (iv) to develop airborne monitoring technologies for verifying workplace safety protocols. This article details reactor design, synthesis parameters, and instruments available to characterize the resulting aerosol nanoparticle size distributions.

Keywords:

• aerosol
• nanoparticle
• occupational health

ACKNOWLEDGMENTS

This work was jointly funded by DuPont and members of the NOSH Consortium, including Procter & Gamble, Dow Chemical, Intel Corporation, Air Products & Chemicals, Inc., Boeing, Degussa, Kimberly-Clark, Rohm & Haas, PPG, General Electric, Health and Safety Executive of the United Kingdom, and the Department of Energy Office of Science who are interested in nanoparticle research and in the advancement of environmental, health, and safety knowledge on how best to manage nanoscale science and engineering safely.