Effectiveness of alcohol-based sanitizer vs alcohol-free sanitizer Coronavirus or COVID-19 (or ‘SARS-CoV-2’) is a newly discovered corona virus. This virus is similar to several human and animal pathogens, including those which cause the common cold as well as SARS (severe acute respiratory syndrome) and MERS (Middle East respiratory syndrome). The United States Center for Disease Control and Prevention (CDC), as well as the World Health Organization (WHO), have recommended the use of alcohol-based sanitizers as an effective way of inactivating the virus on hands and other surfaces. Based on laboratory evidence it has been recommended that a sanitizer with a base solution of 60-80% ethanol or 70% isopropanol is used as these inactivate viruses that have similar physical and genetic properties as COVID-19. Alcohol-based hand sanitizer is effective due to the biocidal activity of coagulation of microbial surface proteins. Maximized effectiveness has been experimentally determined in the alcoholic concentration range of 60-80%, as alcoholic concentration below 50% shows negligible biocidal activity and >90% alcoholic concentrations coagulates the microbial proteins instantly which then act as a ‘shield’ for the rest of the microbial proteins, thus requiring longer contact time for similar results. There are cases being made for the use of alcohol-free hand sanitizers which are made most notably with quaternary ammonium compounds such as benzalkonium chloride. This is a biocidal agent used for surface disinfection, however recent studies have been varied and conflicting. Studies have stated that 0.05-0.2% benzalkonium chloride solutions are unlikely to be effective, and other studies have said that a concentration of 0.05% was quite effective. These conflicting results is why the CDC and WHO have highlighted that alcohol rubs of 60-80% concentration have been significantly more effective and reliable than benzalkonium chloride and other hand rubs. Cleansing with alcohol-based hand sanitizer consistently shows greater efficacy than microbial soaps and non-alcohol-based sanitizers. COVID-19 is a lipophilic enveloped virus and the lipid-dissolving effects of alcohol-based sanitizers is extremely effective against these kinds of viruses (as has been proven against SARS, MERS, Ebola and Zika virus). In conclusion cleansing with alcohol-based hand sanitizer consistently shows greater efficacy than microbial soaps and non-alcohol-based sanitizers. COVID-19 is a lipophilic enveloped virus and the lipid-dissolving effects of alcohol-based sanitizers is extremely effective against these kinds of viruses (Figure 1). Furthermore with the conflicting results on non-alcohol-based sanitizers, the recommendation would be to follow the guidelines and perspective of the CDC and WHO in using 60-80% alcohol-based hand sanitizer in preventing the spread of COVID-19. References

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