Coronavirus: Hand wash or sanitiser - which one is more effective against virus?

New Zealanders are stockpiling alcohol-based hand sanitisers as the coronavirus death toll rises and infections soar to more than 100,000 globally.
New Zealand supermarkets are enforcing restrictions on customers buying hand-sanitiser products amid the outbreak.

At New World Thorndon, a sign on the shelves said because of demand customers were limited to two hand-sanitiser products per person.

Elsewhere, Countdown stores had also limited the number of hand sanitisers customers could buy - also a maximum of two.

Despite the price or product consistency difference, Professor Peter Collignon, an experienced infectious diseases physician and microbiologist in Canberra, said all alcohol-based hand sanitisers were similar.

Lower alcohol-based hand sanitisers are as effective at fighting germs as those with a higher concentration — the only difference is it may take longer to work.

The Australian National University (ANU) specialist, who has worked for the World Health Organisation, said the biggest discrepancy between products was the composition and type of alcohol — ethanol, isopropanol or n-propanol — used.

New Zealand supermarkets are enforcing restrictions on customers hoping to buy hand-sanitiser products amid the coronavirus outbreak. Photo / Getty Images

"It's a dose response – in other words, the closer you get to the right concentration the quicker and more effectively it works - but it doesn't mean 10 per cent less won't work at all," he said.

"It just means it might take 10 per cent longer to work."

He said sanitiser alcohol concentration ranged between 60 and 95 per cent.

Collignon advised against extreme methods to kill germs, such as handwashing with chlorine, and using DIY antibacterial solutions at home which "might do more harm than good" without the right formulation.

He said handwashing with soap and water – regardless of the type or brand – was as effective as using sanitiser from a store.

"It's not the end of the world if you miss out on buying alcohol hand rub because washing your hands with soap and water is also very effective – there is not a huge amount of difference," he said.

"One is just more convenient than the other and contains alcohol.

"You can put it in your pocket and don't have to be near a sink or basin to use it."

But Collignon warned against people excessively washing their hands with either cleaning agent.

He said over-usage of soap and water can lead to dermatitis and people should use common sense.

Last week, Prime Minister Jacinda Ardern told the public to continue with everyday life after New Zealand's first case of coronavirus was confirmed.

But after the announcement panicked shoppers were flooding supermarkets to buy essentials.

"If you need a bottle of milk, go and get it. If you don't, do not react in any other way than you would any other day," Ardern said.

"The public should be going about their daily lives."

- additional reporting NZ Herald