In vitro inactivation of SARS-CoV-2 by ozonated water via novel hand hygiene device

Abstract

Aims The COVID-19 Pandemic has heightened awareness of the need for novel surface disinfectants and hand-hygiene modalities. Ozone gas is an effective surface disinfectant, but toxicity limits its use in human applications. Ozonated water is a safer means to use ozone for disinfection, especially for human antisepsis. However, there are little data available regarding the effectiveness of ozonated water in eliminating severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Methods & Results This study utilizes a novel hand hygiene device that produces a stable ozone concentration of 0.5 +/- 0.1 ppm in water and applies it using a proprietary spray that controls droplet size, velocity, and direction. The Device was used to apply ozonated water to a known quantity of SARS-CoV-2 Delta Variant viral particles on a non-porous surface (glass) for seven seconds. Post-exposure growth was compared to the unexposed matched control utilizing the Spearman-Karber method. Compared to control, ozonated water decreased SARS-CoV-2 viral growth by a mean log10 reduction of 4.33, or > 99.99% reduction. Conclusions These results suggest that the ozonated water, when applied by a spray hand hygiene device, is highly effective at surface disinfection of SARS-CoV-2.

Safety of Prolonged Exposure of Human Skin to Aqueous Ozone in a Test Hand Hygiene Model

“…This model is commonly used as a means to test for dermal irritation and cytotoxicity. Tissue samples (“ETF‐400”) were exposed to AO using a novel hand hygiene device described in more detail elsewhere 12 with a custom‐made tissue holder (“holder”). The device created a consistent concentration of 4 ppm ozone in water, gently sprayed on the tissue specimens using uniform 1mm droplets for a 7 second cycle.…”

“…However, we have been unable to identify any cellular viability studies using full‐thickness skin models following prolonged, repeated exposures typical of healthcare hand hygiene practices 11 . This trial evaluated the cytotoxicity of AO on human skin while simulating the multiple exposures utilized for hand hygiene as in a healthcare setting using a novel hand‐hygiene device modified for this study 12 …”

“… 11 This trial evaluated the cytotoxicity of AO on human skin while simulating the multiple exposures utilized for hand hygiene as in a healthcare setting using a novel hand‐hygiene device modified for this study. 12 …”