Characterization of an aerosol generation system to assess inhalation risks of aerosolized nano-enabled consumer products

Abstract

Objective: The aerosolization of common nano-enabled consumer products such as cosmetics has significantly increased engineered nanoparticle inhalation risks. While several studies have investigated the impact of cosmetic dermal exposures, inhalation hazards of aerosolized cosmetics are much less known but could pose considerable harm to users due to potential co-exposure of nanoparticles and other product components.

Materials and Methods: In this study, we developed a fully automated aerosol generation system to examine the aerosol properties of four aerosolized nano-enabled cosmetics using real-time monitoring and sampling instrumentation. Physicochemical characterization of aerosols was conducted using scanning electron microscopy coupled with energy dispersive x-ray spectroscopy (SEM-EDX). Characterization and calibration of animal exposure pods coupled to the system were also performed by measuring and comparing particle concentrations between pods.

Results and Discussion: Results show peak emissions are shade dependent and varied between 12,000–22,000 particles/cm³ with modal diameters ranging from 36 nm–1.3 µm. SEM-EDX analysis determined that the original products and collected aerosols have similar morphological features consisting of micron-sized particles decorated with nanoparticles and crystalline structures. Mean total particle concentration in pods at 5 and 10 mg/m³ target levels were 2.22E + 05 #/cm³ and 4.33E + 05 #/cm³, respectively, with <10% variability between pods.

Conclusions: The fully automated exposure platform described herein provides reproducible aerosol generation, conforms to recommended guidelines on chemical testing, and therefore is suitable for future in vivo toxicological assessments to examine potential respiratory hazards of aerosolized nano-enabled consumer products.

Keywords:

• Aerosols
• exposure platform
• nano-enabled products
• metal oxide nanoparticles
• inhalation exposure

Acknowledgments

The authors would like to thank Walter McKinney for input and troubleshooting assistance regarding the AGS. SEM-EDX work was performed in part at the Georgia Tech Institute for Electronics and Nanotechnology, a member of the National Nanotechnology Coordinated Infrastructure, which is supported by the National Science Foundation (Grant ECCS-1542174).

Disclosure statement

W.T. Goldsmith was financially compensated by IEStechno, which developed the AGS described in this manuscript.