Ethanol and isopropanol inactivation of human coronavirus on hard surfaces

Abstract

Background The COVID-19 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 supply plain alcohols (EtOH and IPA) or sodium hypochlorite (SH). Aim There are few data showing the efficacy of multiple concentrations of EtOH, IPA, and SH on a human coronavirus (HCoV) dried on surfaces using short contact times. Methods Multiple concentrations of EtOH, IPA, and SH to inactivate high numbers of HCoV under real-life conditions were tested. High concentrations of infectious HCoV were dried on porcelain and ceramic tiles, then treated with multiple concentrations of the alcohols for contact times of 15 sec, 30 sec, and 1 min. Center for Disease Control (CDC) recommended three concentrations of SH were also tested. Reductions in titres were measured by using the tissue culture infectious dose 50 (TCID 50 ) assay. Findings Concentrations of EtOH and IPA from 62% to 80% were very efficient at inactivating high numbers of HCoV dried on tile surfaces even with a 15 sec contact time. Concentrations of 95% dehydrated the virus, allowing infectious virus to survive. The CDC recommended 1/10 and 1/50 dilutions of SH were efficient at inactivating high numbers of HCoV dried on tile surfaces, whereas, a 1/100 dilution had substantially lower activity. Conclusions EtOH, IPA, and SH at multiple concentrations efficiently inactivated infectious virus on hard surfaces, typical of those found in public places. Often no remaining infectious HCoV could be detected.

Biosafety during a pandemic: shared resource laboratories rise to the challenge

“…The ability of an SRL to rapidly respond to the emergence of a new pathogen centers on having established biological safety assessment procedures in place (3, 25, 34), along with a human risk assessment (Appendix). At this time, literature is starting to form a consensus around the stability and inactivation of SARS‐CoV‐2 (14, 16–18, 38–40, 43–45, 50). Exactly how these inactivation methods are applied in SRLs will relate directly to the sample type and the level of risk posed.…”

“…There is extensive literature detailing pathogen inactivation by varying compounds and this should be reviewed when determining the suitability of a fixation protocol (15, 40, 44, 46–49). We are now seeing literature emerging detailing inactivation of SARS‐CoV‐2 with formaldehyde solution (16–18, 50), this is summarized in Table 2. In instances where pathogens are emerging or classified as Risk Group 3/4, all fixation and inactivation protocols are recommended to be validated by the laboratory undertaking the research rather than relying solely on literature (28).…”

“…Viral inactivation validation protocols vary and literature should be reviewed, and local safety officers consulted, when developing protocols for the local context. Viral inactivation validation protocols can be found in these references (15–18, 40, 44, 46–50). In all fixation protocols, it is imperative to consider the: (1) fixative used; (2) how fresh this fixative is; (3) the concentration of the fixative; (4) the time of incubation; and (5) the temperature maintained during incubation (40, 42, 43, 47, 49).…”

“…There is extensive literature detailing pathogen inactivation by varying compounds and this should be reviewed when determining the suitability of a fixation protocol (15,40,44,(46)(47)(48)(49). We are now seeing literature emerging detailing inactivation of SARS-CoV-2 with formaldehyde solution (16)(17)(18)50), this is summarized in Table 2. In Significant value lies in testing fixation protocols to determine potential impact on assays.…”

Inactivation of Human Coronavirus by FATHHOME’s Dry Sanitizer Device: Rapid and Eco-Friendly Ozone-Based Disinfection of SARS-CoV-2

“…Kampf and Colleagues recently analyzed 22 research reports that studied inactivation of SARS and MERS (human coronaviruses/HCoVs of epidemic potential) with biocidal agents, and revealed that surface disinfection using 62–71% ethanol, 0.5% hydrogen peroxide, or 0.1% sodium hypochlorite inactivated the HCoVs within one minute [ 14 ]. Several methods, for instance, high temperature (including autoclaving at 121 °C) [ 21 , 22 ], heat [ 23 , 24 ], sunlight [ 25 ], 70% ethanol [ 26 , 27 ], microwave irradiation [ 28 ], detergents [ 23 ], Trizol reagent [ 23 ], ozone [ 29 ], vaporized hydrogen peroxide [ 30 ], and gamma/UV radiations [ 31 , 32 , 33 ] have been implemented for rapid inactivation of SARS-CoV-2-contaminated surfaces. In 2017, the WHO developed and recommended two alcohol-based hand rub formulations, WHO-I (80% ethanol-1.45% glycerol-0.125% hydrogen peroxide) and II (75% isopropyl alcohol-1.45% glycerol-0.125% hydrogen peroxide) against Ebola virus, human Influenza A virus, and Modified vaccinia Ankara strain [ 34 ].…”