covid-19: how effective is hand sanitizer?
claims that hand sanitizer doesn't work against coronavirus are false. it does, but hand washing is still better.
2 minute read
don't believe claims that hand sanitizer doesn't help prevent the spread of coronavirus. stock/ getty
in the age of the coronavirus panic, misinformation can spread like wildfire. such is the case with a march 1st tweet from a now private account decrying the efficacy of hand sanitizers in combatting viruses. it’s total bunk. that it comes from a supposed scientist surely only exacerbated fears.
here’s where hand sanitizers can be effective:“alcohols are very good at solubilizing fat molecules and causing them to break apart,” says james scott, a professor at the university of toronto’s dalla lana school of public health. “in the case of microorganisms including those viruses that have a surrounding shell of a fat membrane, alcohols can dissolve those causing the cells to die or the virus particles to be ineffective.”however, not all viruses have a fat membrane. those that don’t are not affected by exposure to alcohol. coronavirus falls under the category that would be susceptible to hand sanitizers, while the norovirus, which is prevalent on cruise ships, is not affected.“[there are] three levels of effectiveness that i normally think about. [and] this is how i frame it to students,” says scott. “there’s ineffectiveness, effectiveness and high effectiveness. i think of alcohol-based hand rubs in the middle category in this case. they’re effective but hand washing is the highly effective intervention. [alcohol-based hand rubs] aren’t better than hand washing, but they’re a substitute when hand washing isn’t available.”scott also recommends avoiding touching your face, eyes and nose, but that if you have to, you should wash your hands before. hand sanitizers are simply one tool in the toolbox when it comes to prevention.also, the minimum alcohol percentage for hand sanitizer to be effective is 60 per cent, as some avid vodka drinkers found out recently.
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update: mid-march saw a sevenfold-increase of hand sanitizer sales compared to the same period last year, leading to a shortage of the food ethanol used in alcohol-based sanitizers. as a result, health canada has temporarily authorized the use of technical-grade ethanol in the sanitizer manufacturing.unlike the food-grade ethanol currently used, “hand sanitizers containing acetaldehyde can pose health risks if used more frequently and for a longer period than directed.”to that end, health canada is requiring manufacturers include additional labeling indicating the grade of ethanol used, as well as “specific directions for use and warnings that these products are intended for adult use only, that they should not be used on broken or damaged skin, that they should not be used by women who are pregnant or breastfeeding, and that they should not be inhaled; and information on how to report any adverse reactions to health canada.”
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