Amid the panic over the coronavirus outbreak, it seems, people have forgotten that soap and water are our best defense against disease.

Pharmacies are full of people looking to stock up on hand sanitizer. Demand reached such a fever pitch this week that New York Governor Andrew Cuomo announced the state would be producing a free sanitizer. On Ebay and Amazon, hand sanitizers have been sold at a 200% markup.

Intriguingly, some Twitter users have reported witnessing people frantically stock up on hand sanitizer, but ignoring the soap available.

And yet, soap is the best defense we have, experts say.

“The humble act of washing with soap and water, followed by drying with a clean towel is the gold standard,” Elizabeth Scott, an expert in home and community hygiene and professor at Simmons University, told Insider. “Handwashing with soap employs mechanical action that loosens bacteria and viruses from the skin, rinsing them into the drain.”

The drying that follows makes the skin less hospitable to the bacteria and viruses that can make us sick.

Soap breaks down pathogens, and you’re better off using liquid soap over bar soap in public

Evidence suggests the novel coronavirus is transmitted via droplets from sneezing or coughing that can land on anything, from tables to laptops to credit cards. It can live on surfaces for hours a day. If people touch something a droplet has landed on and then touch their faces, they can get infected.

The pathogen itself is encased in a lipid envelope, or layer of fat. Soap helps destroy that layer of fat, making the virus less capable of infecting you. Hand-washing can also remove pathogens from dirty hands.

Soap contains fat-like substances known as amphiphiles, which are similar to the lipids in the virus’ envelope, Scott told Insider. These amphiphiles compete with the lipids in the virus envelope and deactivate the virus.

While bar and liquid soap are both equally effective, bar soap should not be used in public places, says Scott. Bar soaps are for home only, and shouldn’t be used by people with skin infections.

Hand sanitizer should only be an option when you don’t have access to a sink

Hand sanitizers with an alcohol content that is greater than 62% can also destroy these lipid membranes, according to Scott. But they are ineffective against non-enveloped viruses, like norovirus and rhinovirus, which are variations of the common cold. Plus they provide none of the virus-destroying friction that rubbing your hands together and rinsing provides.

According to Christopher Friese, a professor of nursing, health management and policy at the University of Michigan, hand sanitizer poses three challenges. There must be a high enough alcohol concentration to be effective, the entire surface of the hands and fingers must be covered, and skin irritation may occur. That’s natural when rubbing something that is over 60% alcohol into your skin.

Friese tells all his patients to carry hand sanitizer when they can’t make it to the sink.

Hand sanitizer is universally used in hospitals, nursing homes, and schools. “Maybe it seems more like a ‘medical application,’” said Scott.

Epidemiologist Sandra Albrecht, of Columbia University, theorized that it was the convenience of hand sanitizer that made it more popular than soap. “With sanitizers, you just need one thing – the sanitizer. With soap, you also need access to a clean water source and that’s often not an option when you’re out and about,” she told Insider. “Soap also feels messier than sanitizer, and it also takes longer to use it. Sanitizers are quick and convenient.”

Perhaps that’s why people are fighting over it in chain stores.

Here’s how to wash your hands

According to the CDC, it doesn’t matter whether you use hot or cold water, and there is no added benefit to using antibacterial soap. In fact, there is so little benefit that in September 2016, the FDA had to issue a ruling stating that 19 ingredients commonly marketed in anti-bacterial soaps had zero added benefit and were no longer going to be marketed to people.

“Using soap to wash hands is more effective than using water alone because the surfactants in soap lift soil and microbes from skin, and people tend to scrub hands more thoroughly when using soap, which further removes germs,” says the CDC.

To wash your hands, lather them with soap and scrub for at least 20 seconds. Make sure to focus on places people tend to forget; the back of your hands, between your fingers, and under your nails, where microbes tend to build up. Rinse under clean running water and dry with a clean towel, as germs can easily be transferred to and from wet hands.

This should be simple enough, but a number of studies show that people tend to not wash their hands, or not wash them for the requisite 20 seconds. One 2009 study, cited by the CDC, showed that 69% of men don’t wash their hands after using the bathroom, compared to 35% of women. Another 2013 Michigan State University study found that 95% of people do not wash their hands long enough to kill harmful bacteria. Most recently, in 2019, a YouGov survey of 24,000 Americans found that 40% of them do not always wash their hands with soap after using the bathroom.

So instead of scouring the shelves for hand sanitizer, next time stock up on soap, and wash for 20 seconds.