Ethanol and isopropanol inactivation of human coronavirus on hard surfaces

Abstract

BackgroundThe coronavirus disease 2019 pandemic has greatly increased the frequency of disinfecting surfaces in public places, causing a strain on the ability to obtain disinfectant solutions. An alternative is to use plain alcohols (EtOH and IPA) or sodium hypochlorite (SH).AimTo determine the efficacy of various concentrations of EtOH, IPA and SH on a human coronavirus (HCoV) dried on to surfaces using short contact times.MethodsHigh concentrations of infectious HCoV were dried on to porcelain and ceramic tiles, then treated with various concentrations of the alcohols for contact times of 15 s, 30 s and 1 min. Three concentrations of SH were also tested. Reductions in titres were measured using the tissue culture infectious dose 50 assay.FindingsConcentrations of EtOH and IPA from 62% to 80% were very efficient at inactivating high concentrations of HCoV dried on to tile surfaces, even with a 15-s contact time. Concentrations of 95% dehydrated the virus, allowing infectious virus to survive. The dilutions of SH recommended by the Centers for Disease Control and Prevention (1/10 and 1/50) were efficient at inactivating high concentrations of HCoV dried on to tile surfaces, whereas a 1/100 dilution had substantially lower activity.ConclusionsMultiple concentrations of EtOH, IPA and SH efficiently inactivated infectious HCoV on hard surfaces, typical of those found in public places. Often no remaining infectious HCoV could be detected.