3 Things You Should Know About Hand Sanitizer

Health Canada recommends washing hands with soap and water whenever possible because hand washing reduces the amounts of all types of germs and chemicals on hands. But if soap and water are not available, using a hand sanitizer with at least 60% alcohol can help you avoid getting sick and spreading germs to others.

1. Why is alcohol the main ingredient in most hand sanitizers?

Alcohol is effective at killing different types of microbes, including both viruses and bacteria, because it unfolds and inactivates their proteins.This process, which is called denaturation, will cripple and often kill the microbe because its proteins will unfold and stick together. Heat can also denature some proteins — for example, when you cook an egg, the solidified egg whites are denatured proteins. 

2. Alcohol doesn't kill some microbes very well — why not?

There are different types of bacteria and viruses, and some types are more easily killed by alcohol. For example, E. coli bacteria, which can cause foodborne illness and other infections, are very effectively killed by alcohol at concentrations over 60%. Differences in the outside surface of various bacteria make alcohol sanitization more effective against some of them than others.Similarly, some viruses have an outer wrapping, which is called an envelope, while others are non-enveloped. Alcohol is effective at killing enveloped viruses, including the coronavirus, but is less effective at killing non-enveloped viruses.Whether you are trying to kill bacteria or viruses, many research studies have found that an alcohol concentration of 60% or greater is needed to be effective.

3. If 60% alcohol is good, is 100% better?

Surprisingly, no. Protein denaturation actually works faster when a small amount of water is mixed with the alcohol. And pure alcohol would evaporate too quickly to effectively kill bacteria or viruses on your skin, especially during winter when the air is less humid.

Using 100% alcohol also would dry your skin out very quickly and cause it to become irritated. That might cause you to not sanitize your hands as frequently as needed. This is why most hand sanitizers contain emollients, which are mixtures that help soften and moisturize your skin.