The Science Of Hand-Washing

Mar 19, 2020 By Lauren T, Writer
Lauren T's picture

As a young person, you’ve probably been reminded to wash your hands with soap and water on many occasions. 

With the current coronavirus pandemic, it is important that we wash our hands regularly to avoid contracting or spreading the virus.  

While it’s great to use antibacterial wipes or sanitizers when we don’t have access to a sink, washing our hands with basic soap and water is still the best way to kill germs. So how do soap, water, and some scrubbing eliminate germs? 

How Does Soap Work?

The key to soap’s germ-exterminating abilities lies in its unique structure. 

Soap consists of special pin-shaped molecules, each one composed of a hydrophilic head and a hydrophobic tail. What do hydrophilic and hydrophobic mean?

Think of the hydrophilic heads as water-loving elements — they seek to bond with water. The hydrophobic tails, in contrast, hate water and avoid it, but are attracted to fat, or lipids. 

What happens when you wash your hands with soap and water? As soon as you create a foamy lather, you are surrounding any present germs with soap molecules. Some viruses and bacteria like Ebola and coronaviruses have lipid membranes, to which the hydrophobic tails of soap molecules are immediately attracted. The soap molecules wedge their way into these membranes, breaking them apart and destroying the germs. 

How Can We Wash Our Hands Properly?

To wash your hands thoroughly and efficiently, scrub between your fingers, the backs and palms of your hands, and under your nails for at least 20 seconds.

Singing the “Happy Birthday” song twice (or picking your own song) can help you make sure you’re washing your hands long enough. 

Sources: CDC, NYTimes, Vox, Livescience, Guardian, washourlyrics.com