Can ozone inactivate SARS-CoV-2? A review of mechanisms and performance on viruses

Abstract

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) pandemic has challenged societies around the globe. Technologies based on ozone, a powerful oxidant, have been evaluated to inactivate this virus in aerosols and fomites. However, the high data diversity hinders the possibility of establishing a common ground for determining best practices for the use of these technologies. Furthermore, there is a lack of consensus regarding which are the main mechanisms of ozone virus inactivation. This critical review examined the most relevant information available regarding ozone application in gas-phase for different viruses inactivation (including recent publications dealing with SARS-CoV-2), and pointed towards envelope alteration as the main reaction pathway for enveloped viruses, such as is the case of SARS-CoV-2. It could also be concluded that gaseous ozone can be indeed an effective disinfectant, successfully inactivating viruses such us influenza A H1N1, MERS-CoV, SARS-CoV-1 or even SARS-CoV-2 in aerosols or fomites. In reviewed works, low ozone exposures, just around 0.1-0.4 mg L -1 min, achieve about 4 log 10 of inactivation in aerosols, while exposures between 1 and 4 mg L -1 min may be needed to guarantee an inactivation of 3-4 log 10 in different fomites. Although further studies are required, ozone is an effective candidate to be used against SARS-CoV-2 or other viruses in surfaces and indoor locations.

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

“…Beside the different surrogates employed as models for SARS-CoV-2 in previous studies, viral inactivation is undoubtedly dose-dependent. However, for application purposes it is notably to underline that relative humidity plays a key role in enhancing O 3 mediated inactivation, as the higher RH the more virus is inactivated (data not shown, [15] , [18] ). Thus, specific assays are needed to bring to light how and at which extent RH affects the viral inactivation rates in field tests.…”

“…Recently the virucidal efficacy of the ozone has been reviewed considering the best environmental condition, i.e. 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] .…”

“…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.…”

Inactivation Activities of Ozonated Water, Slightly Acidic Electrolyzed Water and Ethanol against SARS-CoV-2

“…Previous studies have shown that ozone [ 18 ] and hypochlorous acid [ 19 ] damage viral proteins, genomes and lipid layers of biological membranes, such as the viral envelope. Alcohols show more substantial virucidal activity against enveloped viruses than non-enveloped viruses, suggesting that the viral lipid envelope is a potential target of EtOH [ 20 ].…”

Functionalized Masks: Powerful Materials against COVID‐19 and Future Pandemics

“…can deactivate the enveloped viruses via the oxidation of thiol groups in virus proteins and denaturation of proteins. [ 42 , 43 , 44 , 45 ] Similarly, iodophors can release iodine which can penetrate into the membrane and oxidize the proteins’ thiols and also damage the RNA of the virus. Therefore, tethering of the safe oxidizing agents on the surface of personal protection equipment (PPE) can be used as an appropriate approach for fabrication of antiviral PPEs.…”