An expert is warning against using alcohol-free hand sanitisers to protect themselves against the coronavirus.
But one manufacturer says their products not only work, they're better for you than alcohol-based cleaners.
SARS-CoV-2, the virus behind the COVID-19 pandemic, has killed more than 24,000 people and infected 530,000 around the world in the past few months.
New Zealand, with 283 confirmed cases, has shut the borders for the first time in history and is encouraging people to avoid non-essential travel and stay home, where possible, and avoid large gatherings.
One of the most effective ways to avoid getting sick is washing your hands, as the virus can easily be passed into the body by touching the face. While soap and water is effective at killing the virus, it's not always convenient - so hand sanitiser is also in high demand, supermarkets and pharmacies around the country selling out as soon as they get some in stock.
The World Health Organization and Centers for Disease Control and Prevention recommend using a sanitiser that's at least 60 percent alcohol. But some retailers are selling alcohol-free sanitiser.
One Newshub reader sent in screenshots of an exchange they had with a seller on a Facebook market page aimed at Vietnamese Kiwis, selling litres of alcohol-free sanitiser they told potential buyers could kill the virus.
The bottles were labelled 'Hi-Pro', a brand manufactured and sold by Chemical Packers. Manager Wayne Vegar told Newshub they'd never make a claim it could kill the coronavirus, but they can't prevent people from buying their products and selling them online.
"It's just one of those things, and to be honest, very hard to stop."
One that works?
Another popular alcohol-free sanitiser is SpraySafe Protect. Its manufacturers claim it's been proven to kill the SARS virus, which is genetically similar to that which causes COVID-19 (as suggested in its formal name, SARS-CoV-2).
SpraySave Protect's active ingredient is hypochlorous acid, which forms chlorine when added to water. Its manufacturers provided Newshub with studies showing it is effective against viruses like avian influenza, and its own commissioned testing which shows how it's lethal to many forms of bacteria.
"Whilst alcohol and bleach, in sufficiently high dilution ratios are effective, (70 percent for alcohol), there is conclusive New Zealand and global scientific evidence that Spraysafe's hypochlorous acid water technology is as effective or better for killing viruses," said spokesperson Paul Watson.
"Spraysafe is also significantly safer for frequent human use... frequent use of alcohol on the skin can be absorbed onto the body and dry the skin and cause significant side effects in some people. Spraysafe is the safe alternative for frequent use."
He said hypochlorous acid solutions are widely used in Asia, which was hit by the deadly SARS virus in 2003, leading to a heightened awareness of hygiene.
"In New Zealand this is a reasonably new requirement and at Spraysafe we are working hard to educate New Zealanders around the safe and effective alternatives to alcohol- and bleach-based sanitisers."
'You may as well just not bother'
But microbiologist Siouxsie Wiles, who has been the public face of the scientific community in New Zealand during the pandemic, says people should stick to alcohol-based solutions.
"The alcohol in hand sanitisers is the whole reason they work against viruses like coronavirus," she told Newshub on Sunday. "If it doesn't have alcohol, you may as well just not bother."
She said whether a hydrochloric acid could work would "depend on the concentration" but it was safer to stick to alcohol-based products.
Hope for hypochlorous acid
Heather Hendrickson, senior lecturer in molecular biosciences at Massey University, pointed Newshub to the United States' Environmental Protection Agency (EPA) list of "products that meet EPA's criteria for use against SARS-CoV-2, the novel coronavirus that causes the disease COVID-19".
Included amongst them is hypochlorous acid, which the EPA notes has been used to kill noroviruses and rhinoviruses.
But in a recent article for The Conversation, microbiology lecturer Manal Mohammad of the University of Westminster said alcohol-free sanitisers are "less effective than alcohol" at not only killing viruses but other harmful bugs.
"Not only are alcohol-based hand sanitisers found to be effective at killing many types of bacteria, including MRSA and E Coli, they're also effective against many viruses, including the influenza A virus, rhinovirus, hepatitis A virus, HIV, and Middle East respiratory syndrome coronavirus (MERS-CoV)."
But plain old soap and water were best, with soap able to rip open the coronavirus' outer layer and the water wash them away.