For nearly 5,000 years, humans have concocted cleaning products, yet the simple combination of soap and water remains one of the strongest weapons against infectious diseases, including the novel coronavirus. Even so, when outbreaks like COVID-19 occur and panic sets in, people rush to buy all sorts of chemical cleaners, many of which are unnecessary or ineffective against viruses.
Foam hand sanitizers are disappearing from store shelves, even though many lack the necessary amount of alcohol—at least 60 percent by volume—to kill viruses. In countries hardest hit by the novel coronavirus, photos show crews in hazmat suits spraying bleach solutions along public sidewalks or inside office buildings. Experts are dubious, however, of whether that’s necessary to neutralize the spread of the coronavirus.
Using bleach “is like using a bludgeon to swat a fly,” says Jane Greatorex, a virologist at Cambridge University. It can also corrode metal and lead to other respiratory health problems if inhaled too much over time.
“With bleach, if you put it on a surface with a lot of dirt, that [dirt] will eat up the bleach,” says Lisa Casanova, an environmental health scientist at Georgia State University. She and other experts instead recommend using milder soaps, like dish soap, to easily sanitize a surface indoors and outdoors.
To fully understand why health officials keep coming back to soap, it helps to know how the coronavirus exists outside the body, and what early research is saying about how long the virus can linger on common surfaces.