Plasma-Activated Aerosolized Hydrogen Peroxide (aHP) in Surface Inactivation Procedures

Abstract

Introduction: Hydrogen peroxide is a strong oxidant that possesses an antimicrobial activity. It has been successfully used in surface/room decontamination processes either under the form of hydrogen peroxide vapor (HPV) or of vaporized hydrogen peroxide (VHP). Aerosolized hydrogen peroxide (aHP) offers a third alternative. The technology relies on the dispersion of aerosols of a hydrogen peroxide solution often complemented with silver cations. aHP provides an inexpensive and safe approach to treat contaminated rooms but sometimes fails to achieve the 6-log10 reduction limit in the number of viable microorganisms. Methods: Here, we used a venturi-based aHP generator that generates 4 mm in size aerosols from a 12% plasma-activated hydrogen peroxide solution free of silver cations. Results & Discussion: We could successfully and constantly inactivate bacterial growth from biological indicators containing at least 10 6 spores of Geobacillus stearothermophilus placed on stainless steel discs wrapped in Tyvek pouches. We could also show that the biological indicators placed at various locations in a class II biosafety cabinet were equally inactivated, showing that hydrogen peroxide aerosols migrate through HEPA filters. Conclusions: Considering that our method for aerosol generation is simple, reproducible, and highly effective at inactivating spores, our approach is expected to serve as a relatively cost effective alternative method for disinfecting potentially contaminated rooms or surfaces.

Decontamination Validation of a Class II Type A2 Biosafety Cabinet during Laboratory Fumigation

“…HEPA filters function by arresting particles; since dry fogging creates small particles of 7.5 mm in average size, we and others 28 have hypothesized that the PAA fog particles would be stopped by the BSC's HEPA filters, thus making the fog unavailable to decontaminate parts of the BSC past the filters. Our data suggest that the chemical (PAA) was able to traverse across the filters even when the PAA fog particles were arrested by the filter media.…”

“…Several studies have shown how to successfully decontaminate a BSC using various fumigation technologies; however, their approach had entailed decontaminating 1 BSC at a time by directly introducing the fumigant into the cabinet, which is a laborious and time-consuming process. A recent study 28 showed the successful decontamination of a BSC using plasma-activated aerosolized hydrogen peroxide during laboratory fumigation. Here, we investigated whether the same could be accomplished using VHP and PAA dry fog.…”

Air disinfection procedures in the dental office during the COVID-19 pandemic

“…Hydrogen peroxide is a widely recommended agent for daily use in enclosed areas, like incubators, medicine trolleys, laboratory cabinets, rooms and pharmaceutical areas, operating rooms, isolation rooms, intensive care units and general medical wards [26,27]. It has been successfully used in room decontamination processes, either under the form of hydrogen peroxide vapor, vaporized hydrogen peroxide or aerosolized hydrogen peroxide [28]. It uses air particles in the room for spreading the disinfectant.…”

“…The solution of hydrogen peroxide, which is based on pure water and is activated by plasma, coats the surfaces in the room and acts as an oxidizing and disinfecting agent, producing reactive oxygen species (ROS) that attack essential cell components such as DNA, lipids and proteins [28]. The product exhibits bactericidal, fungicidal, virucidal and sporicidal activity.…”

“…Hydrogen peroxide is a more effective antimicrobial agent in the gaseous form, in comparison with the liquid form [27]. It is relatively safe for humans and the environment, because it easily degrades into water and oxygen, and no residue is usually found [26,28]. It is also safe for medical materials and devices.…”