As researchers work around the clock to find out more about coronavirus and how to prevent the spread of the deadly disease one piece of advice has been echoed around the world – wash your hands and wash them well.
Washing your hands is not always an option in public and with liquid soap being snapped up at supermarkets as soon as it is unpacked, more people have turned their attention to hand sanitisers.
The customer demand for the on-the-go hand hygiene products has increased so rapidly that wineries and boutique distilleries have even begun to produce their own versions of alcohol-based sanitisers, but how effective is hand sanitiser against COVID-19?
Hospital grade vs commercial grade sanitiser
For hand sanitiser to be considered effective against viruses it should contain at least 60 per cent alcohol scientist Terri Vinson told Yahoo News Australia.
“60 per cent alcohol, either as isopropyl alcohol or my preference, ethanol is deemed as commercial grade, it’s still effective but in my opinion 70 per cent and above is ideal,” Ms Vinson, who is also an immunology graduate and chemist, said.
The chemist said she preferred ethanol over isopropyl alcohol as ethanol was less toxic if accidentally consumed.
“Seventy per cent is considered hospital grade sanitiser which will be effective against all microbes including viruses,” Ms Vinson said.
Is all hand sanitiser effective against COVID-19?
Ms Vinson said hospital grade hand sanitisers with a 70 per cent or more alcohol content interfered with the coating of the virus, preventing its ability to penetrate living cells, and infect the body.
“Sanitiser destroys the ability for the virus to attack living cells by interfering with its tough protective outer shell of protein and fat,” she said.
But she cautions it’s only truly effective if the sanitiser is over 60 per cent and you have sanitised your hands correctly for 20 seconds.
To use hand sanitiser correctly Ms Vinson follows the recommendations of the Centre for Disease Control (CDC) and is similar to the World Health Organisations recommendation for hand washing.
“According to the CDC when using alcohol-based hand sanitiser you must cover the surface of both hands and rub together for around 20 seconds until the hands feel completely dry,” she said.
How long does hand sanitiser last once applied?
While hand sanitiser is a good alternative to hand washing, just like soap and water, as soon as you touch something else, your hands have picked up more bacteria.
“It only works for a short time and is only working on viruses and microbes that were already on your hands, you must repeat the process if your hands have touched any surface that may be contaminated,” Ms Vinson said.
The New England Journal of Medicine has stated that COVID-19 can remain active on plastic and stainless steel surfaces for up to 72 hours so the chemist advises using anti-bacterial spray on surfaces.
“It is important to make sure you are not only cleaning your hands, but sanitising anything else you may have touched while exposed to harmful microbes,” Ms Vinson said.
Does hand sanitiser expire?
If you are still using the same bottle of hand sanitiser that has been in your purse for years it may still be effective.
Ms Vinson said commercial grade hand sanitiser usually has around a three-year shelf life once opened, but the expiry date depends on the ability of the sanitiser to maintain its alcohol content.
“If the product is commercial grade once opened, the alcohol may evaporate rendering the product less effective, particularly to deactivating the virus particle. However, expiry will take much longer with a higher hospital grade product,” Ms Vinson said.
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