As the coronavirus death toll rises and infections soar to more than 90,000 globally, millions of Australians are stockpiling alcohol-based hand sanitisers.

The surge in demand has seen prices skyrocket as many stores have run out of stock.

Supplies are also being resold online for as much as $40 per 50ml bottle on eBay.

Shoppers have vented their frustrations online with many complaining at having to buy cheaper less-popular brands.

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 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.

"It's a dose response - in other words, the closer you get to the right concentration the quicker and more effective 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," Prof Collignon said, adding sanitiser alcohol concentration ranged between 60 and 95 per cent.

Prof Collignon advised against extreme methods to kill germs, such as handwashing with chlorine, and using DIY antibacterial solutions at home which "it 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 Prof 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 commonsense.

Prime Minister Scott Morrison has told Australians who are madly stockpiling items that they should get their information from "trusted official sources".

"It is important to get information from the trusted official sources. That is what I have suggested whether it is through the information line, the incident response centre, not to be responding to what I have seen, some rightly - rather wildly speculative reports out there," he said.

"That is not helping anybody for the people running around and making all sorts of wild speculations is not helping anybody."

Prof Collignon's comments come as the WHO advised businesses to promote handwashing as well as placing hand-sanitising dispensers in prominent places in the workplace.

"Keep communicating and promoting the message that people need to stay at home even

if they have just mild symptoms of COVID-19," the document read.

"Encourage employees to wash their hands regularly and stay at least one metre away

from people who are coughing or sneezing.

"Develop a contingency and business continuity plan for an outbreak in the communities where your business operates."

Prof Collignon said being vigilant, sensible and following "the basic things we do every winter" was the biggest preventive measures against COVID-19.

"It's probably very similar to other respiratory illnesses we see every winter but we don't know yet," he said.

"So what we need to do is if we are sick we need to keep away from other people.

"Don't go to work. Don't travel on public transport. Even at home, keep your distance from other members of your family.

"Don't forget to keep your hands clean. Wash them and do not touch your eyes or mouth - 40 per cent of people touch their face at least once every 30 minutes."