Examination of Nanoparticle Filtration by Filtering Facepiece Respirators during the COVID-19 Pandemic

摘要: The onset of the COVID-19 pandemic in spring 2020 resulted a spike demand for face masks and respirators Due to their effectiveness at filtering aerosols that could potentially contain viruses, N95-type facepiece (FFRs) are frequently used by healthcare workers first responders However, due shortage domestic N95 FFRs US beginning pandemic, internationally produced were imported deployed under an Emergency Use Authorization Food Drug Administration concerns raised time, there was urgent need verify usability In this study, we summarize our characterization nanoparticulate filtration performances 136 such respirators, measured between April 1 June 30, Our results indicate about 42% showed efficiencies better than 90% (≤10% penetration), but only 17% performed 95% (≤5% penetration) On other hand, 35% below 80% (≥20% A representative subset devices analyzed origin variations performance We found efficiency increased with level electrostatic charge on poor sourced be traced lack mechanisms Furthermore, electrostatics shifted particle size which aerosol penetration through FFR maximal from around 200 nm less 100 highest-performing FFRs, range largely goes undetected standardized tests © 2021 American Chemical Society