Or are you?

This post isn’t created to spread fear or panic, so let me start off by saying, if you got your hands on some alcohol-based sanitizers (or is it the other way around 😝) that are sold from reputable brands then you are definitely much better protected than those using non-alcohol-based sanitizers or the “DIY” versions as discussed in Myth No. 5.

So on what basis am I calling the protective powers of alcohol-based hand sanitizers a myth? Especially when even the World Health Organization has published recommended formula for them?

Let’s begin by diving into the biological structure of the virus and bacteria that we are aiming to defend against. The corona-virus, similar to the flu virus, is enveloped in an outer shell of protein. Bacteria are similarly enveloped in cell walls. The effect of alcohol is to destroy the outer shells or membranes protecting these virus or bacteria, in turn killing them*. That said, there are some things to watch out for to ensure the alcohol has a chance to properly do its job.

1. Concentration of alcohol (or ethanol) must be at 60 to 95%. Lower than 60%, the alcohol content isn’t strong enough to denature the virus or bacteria protein. Higher than 95%, there isn’t enough water content present to enable sufficient time for the alcohol to do its job before it evaporates.

 2. Enough sanitizer must be used to coat all skin surface. This is an obvious one, and enough translates to 3 mL or about a palmful.

3. Ensure your hands aren’t dirty. Foreign matter on your hands (such as grease or dirt) will inhibit the sanitizer from killing viruses or bacteria present by making it difficult for the alcohol to reach the protein envelops. 

4. Don’t be too quick to wipe your hands after. Hand sanitizers in a gel format often leave behind a “ sticky” feeling or residue and some people will be tempted to wipe it off before the gel dries up. This actually reduces the sanitizing power as there are polymers added to create the gel consistency for the purpose of allowing sufficient time for the alcohol to kill off the germs.

All in all, and I can’t repeat enough, hand washing is best. With plain, old soap and water for 20 seconds. In addition to the limitations noted above, the denatured microbes continue to remain on your hands after the use of alcohol-based sanitizers. Whereas soap and water will not only disrupt the envelops of the virus and bacteria, they will remove the microbes (as well as any dirt or grease)  from your skin altogether. 

*Note that alcohol-based sanitizers are not effective at killing viruses not enveloped in an outer shell (such as noro-virus).

References

https://www.compoundchem.com/2020/03/04/hand-sanitisers/?fbclid=IwAR1zuU8QB2nmMjYMvIPdaGZR2Rx3fHrhpZ-zo-wS7T2KOJUu7SvL5AaQ9zA

https://www.cdc.gov/handwashing/show-me-the-science-hand-sanitizer.html

https://cen.acs.org/business/consumer-products/hand-sanitizer-does-keep-hands/98/i12