Palli Thordarson, chemistry professor at the University of New South Wales, writing for The Guardian:
Viruses can be active outside the body for hours, even days.
Disinfectants, liquids, wipes, gels and creams containing alcohol
are all useful at getting rid of them — but they are not quite as
good as normal soap.
When I shared the information above using Twitter, it went
viral. I think I have worked out why. Health authorities have been
giving us two messages: once you have the virus there are no drugs
that can kill it or help you get rid of it. But also, wash your
hands to stop the virus spreading. This seems odd. You can’t, even
for a million dollars, get a drug for the coronavirus — but your
grandmother’s bar of soap kills the virus.
So why does soap work so well on the Sars-CoV-2, the coronavirus
and indeed most viruses? The short story: because the virus is a
self-assembled nanoparticle in which the weakest link is the lipid
(fatty) bilayer. Soap dissolves the fat membrane and the virus
falls apart like a house of cards and dies — or rather, we should
say it becomes inactive as viruses aren’t really alive.
I was not aware until this week that good old-fashioned soap is significantly more effective than alcohol-based disinfectants.