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Things you need to know about hand sanitisers

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

Alcohol is effective at killing different types of microbes, including viruses and bacteria, because it unfolds and inactivates their proteins.

This process, is called denaturation and often kills the microbe because the proteins unfold and stick together. Heat can also denature some proteins — i.e, when you cook an egg, the solidified egg whites are denatured proteins.

2. Alcohol actually doesn't kill some microbes very well

Some types of viruses adn bacteria are more easily killed by alcohol. 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 the bacteria make sanitising with alcohol more effective against some of them than others.

Some viruses have an outer wrapping, called an envelope and alcohol is effective at killing enveloped viruses, including the coronavirus, and is less effective at killing non-enveloped viruses.

If you are trying to kill bacteria or viruses, research has found that an alcohol concentration of 60% or higher is needed to be effective.

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

Basically - no. Protein denaturation works faster when a small amount of water is mixed with the alcohol to slow down the evaporation. Pure alcohol would evaporate too quickly to effectively kill bacteria or viruses on your skin, especially during winter when the air is less humid.

100% alcohol also dries your skin out very quickly and could cause it to become irritated, which could then 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.

4. Are homemade hand sanitizers a good idea? Most experts wil say no. There are many do-it-yourself formulas online, with some that using vodka. The problem with vodka is that it is 80 proof, meaning it is only 40% alcohol and that is not high enough to kill microbes effectively.

Most homes may have rubbing alcohol stashed in the bathroom and this could seem like a good alternative, but if you are already near a sink, the best is to wash you hands thoroughly for 20 seconds with soap and hot water.

Thank you for this useful information.


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