UPDATED: New research contends that non-alcoholic hand sanitisers are just as effective at disinfecting surfaces against COVID-19 as alcohol-based sanitisers.
Health authorities, including the US Centers for Disease Control and Prevention (CDC), have held that sanitisers needed to be 60 per cent alcohol-based to safeguard against the virus. And recently, consumer advocate CHOICE warned against buying White Knight hand sanitiser, sold at many petrol stations and online in Australia, because independent testing found it had 52 per cent alcohol, not the 75 per cent it claimed. In Europe, an investigation of sanitisers by Which? found three of 18 sold at online marketplaces Etsy and eBay failed to show the same alcohol levels claimed on the product listing page or the packaging.
But the study out of Brigham Young University, published in the Journal of Hospital Infection, found three non-alcoholic disinfectants, using benzalkonium chloride (BKC), killed 99.9 per cent of the virus within 15 seconds.
“Our results indicate that alcohol-free hand sanitiser works just as well, so we could – maybe even should – be using it to control COVID,” said lead study author Benjamin Ogilvie.
Alcohol-free hand sanitisers, which are also effective against the common cold and flu viruses, are cheaper to make and more pleasant for users.
“Benzalkonium chloride can be used in much lower concentrations and does not cause the familiar ‘burn’ feeling you might know from using alcohol hand sanitiser. It can make life easier for people who have to sanitise hands a lot, like healthcare workers, and maybe even increase compliance with sanitising guidelines,” Mr Ogilvie said.
PhD student Antonio Solis Leal said having more options to disinfect hospitals and public places was critical, given shortages being experienced in some parts of the world.
“People were already using it before 2020,” said Brigham Young professor and co-author Brad Berges.
Prof. Berges believes the Brigham Young findings “may actually provide a change in (US) government directions about hand sanitiser”.
“Hand sanitiser can play an especially important role in controlling COVID. This is information that could affect millions of people,” he said.
“It just seems like during this pandemic, the non-alcohol-based hand sanitisers have been thrown by the wayside because the government was saying, ‘we don’t know that these work’, due to the novelty of the virus and the unique lab conditions required to run tests on it.
“A couple of others have looked at using these compounds against COVID, but we’re the first to actually look at it in a practical time frame, using four different options, with the realistic circumstance of having dirt on your hands before you use it.”
BKC is the key ingredient in many antibacterial soaps and costs less to produce in effective amounts than alcohol.
Fast Company enlisted David Edwards, a pathogen expert at Harvard, to review the study. “BKC is a well-known antimicrobial … the results of the study here are not surprising,” he said.
Fast Company concluded: “If BKC were recommended by the CDC, the availability of hand sanitiser would go up, while the costs could go down, since you need far less BKC than alcohol for sanitiser to be effective. Whereas you need a 60 per cent concentration of alcohol in hand sanitiser for it to be effective, you only need a 0.2 per cent concentration of BKC.
“One gallon (3.78 litres) of BKC could make 500 gallons of hand sanitiser, while the same quantity of alcohol could make 1.4 litres of alcohol hand sanitiser,” said Mr Ogilvie. He estimates BKC sanitisers cost one-third as much to produce as alcohol-based sanitisers.
“One nice advantage of BKC … is that it does not sting hands or irritate skin like alcohol does,” said Mr Ogilvie. “This can perhaps lead to better compliance among healthcare workers.”
Which hand sanitiser do you use?
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