Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 2 of 2
Full-Text Articles in Medicine and Health Sciences
A Method To Measure The Partitioning Coefficient Of Volatile Organic Compounds In Nanoparticles, Guiying Rao, Jeonghyeon Ahn, Abigail Evans, Michelle Casey, Eric P. Vejerano
A Method To Measure The Partitioning Coefficient Of Volatile Organic Compounds In Nanoparticles, Guiying Rao, Jeonghyeon Ahn, Abigail Evans, Michelle Casey, Eric P. Vejerano
Faculty Publications
The partitioning behavior of volatile organic compounds (VOCs) into nanoparticles is less studied compared to those of semivolatile organic compounds (SVOCs) because of the lower concentration of the VOCs that is expected to partition into particles. One challenge in measuring the accurate partition coefficient of VOCs is quantifying their low mass fraction that sorbed on nanoparticles and differentiating them from the high VOC concentrations present in the gas-phase. Systematically characterizing the partitioning coefficient at a specific environmental condition is also difficult when sampling in the field. During field sampling, thermal and non-thermal issues such as sampling artifacts and non-equilibrium conditions …
A Letter To Reconsider The Conditions For Testing Decontaminated N95 Respirators For Emergency Reuse To Address Shortage, Eric P. Vejerano, Jeonghyeon Ahn
A Letter To Reconsider The Conditions For Testing Decontaminated N95 Respirators For Emergency Reuse To Address Shortage, Eric P. Vejerano, Jeonghyeon Ahn
Faculty Publications
The battle with COVID-19 pandemic has resulted in the shortage of personal protective equipment, particularly, N95 respirators. Healthcare workers who reused N95 respirators may resort to unproven methods of cleaning/sterilization that can severely compromise the respirators’ filtration efficiency. A recently issued guideline will test decontaminated N95 respirators against particles with a median diameter of 0.075 ± 0.020 µm at a flow rate of 85 L min–1. For emergency reuse, these conditions may be too stringent. N95 respirators tested at this flow rate had predicted efficiencies of < 69%, assuming complete degradation of their electrostatic coating. Experimental efficiencies were ~15% lower. For emergency reuse, we recommend to either adjust the flow rate closer to normal breathing, or the size of the test particle should reflect that of virus-laden respiratory aerosols (~> 0.5 µm). By reconsidering the test conditions, a substantial fraction of used/decontaminated respirators can …