HAND sanitisers sold on popular online marketplaces are making misleading claims about alcohol content and risk leaving consumers unprotected against COVID-19 because they do not contain recommended levels.

That is the conclusion of new research by consumer organsiation Which? which found that the worst offending hand sanitiser had an alcohol content of just 10 per cent, a fraction of the 75 per cent claimed – leaving people using it particularly exposed to bacteria and viruses.

Which? provided some tips on what you have to watch out for when buying hand sanitisers.

First they say you should use the correct type of sanitiser. It recommended choosing one with 60-90 per cent alcohol content (ethanol or isopropanol) as it's most effective against viruses like COVID-19.

READ MORE: Extremely concerning': Warning over hand sanitisers sold on online marketplaces that 'fail to protect' from Covid-19

It added: "If it’s not possible to wash your hands, sanitise after touching any surfaces or items that could be contaminated, such as hand rails, doors or your face mask. Use enough hand sanitiser to cover the full surface area of your hands – not forgetting your wrists and nails.

"Rub it in for at least 20 to 30 seconds – or most importantly, until your hands are dry."

Why is alcohol important in hand sanitiser?

The alcohol found in hand sanitisers is usually ethanol, isopropanol or a mixture of the two. Alcohol destroys COVID-19 by dissolving its outer layer which inactivates it.

Video: Watch to find out the most common hand sanitiser mistakes you need to avoid.

Ethanol is what you get in drinking alcohol, while isopropanol is what’s more commonly known as ‘rubbing alcohol’. However, rubbing your hands with vodka or gin is not going to be as effective as a proper hand sanitiser because the alcohol in standard spirits is closer to 40 per cent.

At the right percentage volume, starting from at least 60 per cent according to the World Health Organisation (WHO), alcohol is effective against bacteria and viruses.

However, if the hand sanitiser doesn’t contain a high enough percentage of alcohol, then it might not kill off the bacteria and viruses on your hands.