Decontamination of High-Efficiency Mask Filters From Respiratory Pathogens Including SARS-CoV-2 by Non-thermal Plasma

Abstract

The current pandemic resulted in a rapidly increasing demand for personal protective equipment (PPE) initially leading to severe shortages of these items. Hence, during an unexpected and fast virus spread, the possibility of reusing highly efficient protective equipment could provide a viable solution for keeping both healthcare professionals and the general public equipped and protected. This requires an efficient decontamination technique that preserves functionality of the sensitive materials used for PPE production. Non-thermal plasma (NTP) is a decontamination technique with documented efficiency against select bacterial and fungal pathogens combined with low damage to exposed materials. We have investigated NTP for decontamination of high-efficiency P3 R filters from viral respiratory pathogens in comparison to other commonly used techniques. We show that NTP treatment completely inactivates SARS-CoV-2 and three other common human respiratory viruses including Influenza A, Rhinovirus and Adenovirus, revealing an efficiency comparable to 90°C dry heat or UVC light. Unlike some of the tested techniques (e.g., autoclaving), NTP neither influenced the filtering efficiency nor the microstructure of the filter. We demonstrate that NTP is a powerful and economic technology for efficient decontamination of protective filters and other sensitive materials from different respiratory pathogens.

Inactivation of SARS-CoV-2 and Other Enveloped and Non-Enveloped Viruses with Non-Thermal Plasma for Hospital Disinfection

“…Other studies have reported viral inactivation with different NTP devices but not without drawbacks . The need of vacuum systems, feed gases, ,− high gas temperatures that can damage the materials, , or very long treatment times make those devices unsuitable for routine hospital use. Moreover, gas-fed NTP, such as plasma jets, could present additional health risks, as the constant gas flow could blow microdroplets that carry viruses and other contaminating particles into the surrounding environment, thus further spreading its reach.…”

Mechanisms leading to plasma activated water high in nitrogen oxides

“…They vary in the structure of electrodes, the type of power sources, a pulse/continual regime and the composition of the used atmosphere. Thanks to these techniques, NTP was successfully employed in a wide range of applications, starting from rendering surfaces hydrophilic [9], their decontamination [10], antifungal and conservation treatment of food and seeds causing extension of their shelf life [8,[11][12][13] and green technology [14] for the effective disinfection of respirators and other medical equipment [15,16].…”

Non-thermal plasma disinfecting procedure is harmless to delicate items of everyday use

“…NTP exhibits antimicrobial 2 – 7 and antiviral effects 8 , 9 , and its applications have been the subject of intensive research in recent decades 6 , 10 – 12 . As NTP is typically generated in ambient air, the largest proportion of microbicidal and virucidal agents are reactive oxygen species (ROS) and reactive nitrogen species (RNS) 13 .…”

“…This topic became of relevance in reported NTP applications for the decontamination of protective equipment during the pandemic of COVID-19. Several studies were published at this time of lack of protective equipment, mainly face masks and respirators 8 , 9 , 18 – 20 . In our previous study Obrová et al 8 , we reported that NTP can be advantageously used for the decontamination of respiratory P3 R filters without affecting their filtration capacity.…”

“…Several studies were published at this time of lack of protective equipment, mainly face masks and respirators 8 , 9 , 18 – 20 . In our previous study Obrová et al 8 , we reported that NTP can be advantageously used for the decontamination of respiratory P3 R filters without affecting their filtration capacity. Due to the general urgency, these studies, including ours, reported a reliable but simple demonstration of decontamination and reuse of the treated objects, while more complex studies aimed at the modifications and possible damage to the studied materials were carried out only marginally.…”