Critical Review and Research Needs of Ozone Applications Related to Virus Inactivation: Potential Implications for SARS-CoV-2

Abstract

Ozone disinfection has demonstrated high efficacy against enveloped and non-enveloped viruses, including viruses similar in morphology to SARS-CoV-2. Due to this efficacy, numerous gaseous and aqueous phase ozone applications have emerged to potentially inhibit virus persistence in aerosols, surfaces, and water. This review identifies the exposure requirements for virus inactivation and important safety considerations for applications within the built environment (i.e. occupied/unoccupied spaces, air/water/wastewater treatment) and healthcare settings (i.e. ozone therapy, dentistry, handwashing, treatment of personal protection equipment (PPE)). Current research needs are presented to advance the utilization of ozone as a mitigation strategy.

Coronaviruses and SARS-CoV-2 in sewerage and their removal: Step by step in wastewater treatment plants

“…With regards to SARS-CoV-2, further research is needed about the disinfection with ozone to determine the efficacy of commercial devices and the minimum ozone CT values (residual concentrations and contact time) to meet the required log10 virus reduction. The current knowledge about the efficacy of ozone for the inactivation of other viruses suggests that ozone is likely to be highly effective at inactivating SARS-CoV-2 in water ( Morrison et al, 2021 ). This statement derives from many studies which demonstrated that ozone at low CT was effective at rapidly inactivating various types of viruses in wastewater or potable water with reductions of 4-log10 ( Morrison et al, 2021 ).…”

“…The current knowledge about the efficacy of ozone for the inactivation of other viruses suggests that ozone is likely to be highly effective at inactivating SARS-CoV-2 in water ( Morrison et al, 2021 ). This statement derives from many studies which demonstrated that ozone at low CT was effective at rapidly inactivating various types of viruses in wastewater or potable water with reductions of 4-log10 ( Morrison et al, 2021 ).…”

Ozone Treatment Is Insufficient to Inactivate SARS-CoV-2 Surrogate under Field Conditions

“…Therefore, the ozonized water has been shown to inactivate numerous RNA and DNA viruses, including SARS-CoV-2 [ 20 , 21 ]. Due to shortages of PPE at the beginning of the COVID-19 pandemic, gaseous ozone disinfection becomes an attractive tool, providing further use of disposable protective equipment [ 8 , 22 , 23 ]. Moreover, the low cost of ozone generators makes them easily accessible; therefore, they began to be widely applied to decontaminate many closed spaces, such as offices, classrooms, churches, hospitals, and public utility buildings.…”

Experimental and CFD evaluation of ozone efficacy against coronavirus and enteric virus contamination on public transport surfaces

“…The first uses of ozone was the drinking water disinfection with early full-scale treatment plants since the beginning of XX century [13] . Although there is a vast literature on the ozone concentration and exposure times needed for bacterial and protozoan inactivation in wastewater treatment, scarce data are available for controlling viral contamination [14] . Previous data showed that both murine coronavirus and SARS-CoV-1 [15] , [16] are readily inactivated by O 3 treatment especially when combined with high relative humidity (RH) and this outcome has been conveyed to SARS-CoV-2 based on a recent computational analysis [17] .…”

“…temperature and humidity, the ozone concentration and contact times, for a broad number of independent viruses [18] . The ozone could be an efficient potential disinfectant against the SARS-CoV-2 because his lipid envelope can be readily degraded by ozone [14] , [18] . However, robust experimental evidence on the efficacy of this disinfectant under realistic conditions checking also for residual viral viability is still lacking finally limiting the establishment of well-defined decontamination procedures that is a paramount priority.…”