Decontamination Assessment of Nanofiber-based N95 Masks

Abstract

As the world battles with the outbreak of the novel coronavirus, it also prepares for future global pandemics that threaten our health, economy, and survivor. During the outbreak, it became evident that use of personal protective equipment (PPE), specially face masks, can significantly slow the otherwise uncontrolled spread of the virus. Nevertheless, the outbreak and its new variants have caused shortage of PPE in many regions of the world. In addition, waste management of the enormous economical and environmental footprint of single use PPE has proven to be a challenge. Therefore, this study advances the theme of decontaminating used masks. More specifically, the effect of various decontamination techniques on the integrity and functionality of nanofiber-based N95 masks (i.e. capable of at least filtering 95% of 0.3 μm aerosols) were examined. These techniques include 70% ethanol, bleaching, boiling, steaming, ironing as well as placement in autoclave, oven, and exposure to microwave (MW) and ultraviolet (UV) light. Herein, filtration efficiency (by Particle Filtration Efficiency equipment), general morphology, and microstructure of nanofibers (by Field Emission Scanning Electron microscopy) prior and after every decontamination technique were observed. The results suggest that decontamination of masks with 70% ethanol can lead to significant unfavorable changes in the microstructure and filtration efficiency (down to 57.33%) of the masks. In other techniques such as bleaching, boiling, steaming, ironing and placement in the oven, filtration efficiency dropped to only about 80% and in addition, some morphological changes in the nanofiber microstructure were seen. Expectedly, there was no significant reduction in filtration efficiency nor microstructural changes in the case of placement in autoclave and exposure to the UV light. It was concluded that, the latter methods are preferable to decontaminate nanofiber-based N95 masks.

Comparative Evaluation of Microorganism Disinfection Methods for N95 Respirators

“…The use of 70% ethanol clearly reduced the fi ltration effi ciency by approximately 40%, even with a single treatment. Two mechanisms have been proposed for this degradation: electrostatic discharge and surface tension interactions [14,15]. If the electrostatic discharge hypothesis is the major mechanism of N95 degradation, 0.1% hypochlorous acid solution treatment would also have shown similar degradation in this study, but no signifi cant change in N95 integrity was observed in our study.…”

Self-Sanitization in a Silk Nanofibrous Network for Biodegradable PM0.3 Filters with In Situ Joule Heating

“…Face masks are sanitized to eliminate pathogens using various methods such as dry heat, chemical reagents, nanoparticle implantation, and exposure to steam, supercritical CO 2 , UV, and solar irradiation. − While dry heat and steam offer simple sanitization of face masks, the continuous temperature rise can lower filtration performance . Conversely, UV and solar light irradiation effectively neutralize pathogens without compromising FE. , However, high-power UV requires specific chambers, and light irradiation may partially disinfect due to limited penetration. , Chemical sanitization involves agents like detergent, alcohol (IPA and ethanol), H 2 O 2 , hypochlorite, and ethylene oxide, ensuring thorough disinfection .…”