Why it’s important
Because of alcohol’s amazing ability to stop bacteria in its tracks, it is important to look at the label or datasheet for any hand sanitiser before you buy. It’s very easy to pick up an alternative with no knowledge of whether it will be as effective as a high alcohol content solution but what is certain is that it is unlikely that any alternative will be as reliable and widely trusted as alcohol gel, which has been proven to be safe and consistent. The Center for Disease Control and Prevention (CDC) advise that a 60-95% alcohol concentration is necessary for an effective hand sanitiser, while the World Health Organisation (WHO) recommends 70%. Advice and testing show that alcohol concentration lower than this may not work as well and will simply reduce the growth of viruses and bacteria but not actually kill them.
The Science Bit
If you are interested in more information as to why medical institutions put such an emphasis on alcohol, it is because of “Denaturation”. This is the technical term for alcohol’s process for destroying germs and means that the alcohol changes the bacteria from its original state. The “alcohol” products in a gel are most frequently alcohol compounds, such as ethyl alcohol, or ethanol, which can break down bacteria from the inside out. By first bonding to the bacteria, the alcohol is then able to bond with the molecules which make up the membranes protecting the inside of the virus and make them more soluble in water. The membrane immediately begins to lose its structural integrity and collapses, leaving holes where the alcohol can enter the bacteria and disrupt proteins that are in the water. This is how alcohol “denatures” or alters the bacteria. The whole molecule will then eventually break down which means that the alcohol has effectively done its job.
So now you know the science behind the advice, it’s best to ensure when buying hand sanitiser that it’s at least 60% alcohol content – or above – if you want to be absolutely sure of having clean, germ free hands.