Many people have been bulk-buying hand sanitiser to protect themselves from becoming infected by the coronavirus, but an expert has explained why soap is a much better option.
People are continuing to panic-buy and last month some New Zealand supermarkets were forced to limit hand sanitisers to "two per customer".
But University of New South Wales supramolecular chemistry expert Professor Palli Thordarson has explained why soap and water are the best when it comes to hygiene concerns amid the COVID-19 outbreak.
"The soap dissolves the fat membrane and falls apart like a house. Disinfectants, or liquids, wipes, gels, and creams containing alcohol - have a similar effect but are not really quite as good as normal soap," Prof Thordarson explained in a series of Twitter posts on Monday.
Normal soap does the job just fine, he said, adding it dissolves the "glue" that holds the virus together.
"The soap also outcompetes the interactions between the virus and the skin surface. Soon the viruses get detached and fall apart like a house of cards due to the combined action of the soap and water."
According to Prof Thordarson, alcohol - a common ingredient in hand sanitisers - isn't as good as soap at dissolving the virus.
He said "nothing beats soap".
"The virus detaches from the skin and falls apart very readily in soapy water."
People are also urged to be extra careful making regular contact with their faces.
"They [viruses] can stay active for many hours on surfaces and then get picked up by touch," he said. "They then get to our face and infect us because most of us touch the face quite frequently."