Hand sanitiser vs. Soap and water

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

Australian pharmacies are currently out of stock of hand sanitiser. Demand have reached a new high that distillers around the country have stepped in to diversify their distillery capabilities to produce more hand sanitisers for hospitals and the public.

In some countries, government-based foundation have stepped in to distribute hand sanitisers to their local communities. Locals are asked to bring their own empty bottles to collection points, where a big vat of hand sanitiser will be dispensed free of charge to residents. This is one of many steps taken by some Singapore corporations to ensure that there is health equality and fair distribution of health resources in times of crisis.

Intriguingly, the frantic panic buying of hand sanitisers have led to many shelves empty of alcohol hand rubs, but many liquid and bar soaps left.

And yet, soap is the best defence 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. "Hand washing 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 barsoap in public

Coronavirus can be transmitted via droplet from our sneeze and saliva, and spread to frequently-touched items like your mobile phones and laptops. In addition, these viruses can live on surfaces for 24 hours. If people touch something a droplet has landed on and then touch their faces especially nose, eyes and mouth, 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 sanitiser should only be an option when you don't have access to a sink

Hand sanitisers 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 sanitiser 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.

Epidemiologist Sandra Albrecht, of Columbia University, theorised that it was the convenience of hand sanitiser that made it more popular than soap. "With sanitisers, you just need one thing – the sanitiser. 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 sanitiser, and it also takes longer to use it. Sanitisers are quick and convenient."

Perhaps that's why people are fighting over it in our supermarkets and pharmacies.

Here's how to wash your hands

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. 

The World Health Organization has a simple infographic on how to wash your hands properly.

A 2009 study showed that 69% of men do not wash their hands after using the bathroom. This is concerning as most men are aware that tiny droplets of urine may splatter on their hands while using the urinals. Even if they did wash their hands, 40% of Americans surveyed do not always wash their hands with soap and water, but just rinsing with water only.

This is a worrying trend and should be tackled more effectively using public media campaigns about hand washing.

One American mother has even gone a step further to demonstrate the amount of bacteria in our hands using different sanitation methods. Instead of using a petri dish with bacteria growing agar, she used a simple slice of white bread. Though not all bacteria will grow on bread, her simple experiment proved an important point - wash your hands, do not heavily rely on hand sanitisers!

With that said, instead of scouring the shelves for hand sanitiser, next time stock up on soap, and wash for 20 seconds, and that's to the song of "Happy Birthday" twice!