Inactivation of SARS-CoV-2 and influenza A virus by spraying hypochlorous acid solution and hydrogen peroxide solution in the form of Dry Fog

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of coronavirus disease 2019 (COVID-19), is transmitted by droplet and contact infection. SARS-CoV-2 that adheres to environmental surfaces remains infectious for several days. We herein attempted to inactivate SARS-CoV-2 and influenza A virus adhering to an environmental surface by spraying aerosolized hypochlorous acid solution and hydrogen peroxide solution in the form of Dry Fog (fog that does not wet objects even if touched). SARS-CoV-2 and influenza virus were dried on plastic plates and placed into a test chamber for inactivation by the Dry Fog spraying of disinfectants. The results obtained showed that Dry Fog spraying inactivated SARS-CoV-2 and influenza A virus in time- and exposed disinfectant amount-dependent manners. SARS-CoV-2 was more resistant to the virucidal effects of aerosolized hypochlorous acid solution and hydrogen peroxide solution than influenza A virus; therefore, higher concentrations of spray solutions were required to inactivate SARS-CoV-2 than influenza A virus. The present results provide important information for the development of a strategy that inactivates SARS-CoV-2 and influenza A virus on environmental surfaces by spatial spraying.