How Soap Works
by Joe Johnson, on March 24,2020
Handwashing is one of the most important things you can do to stay safe during this time of the COVID-19 pandemic. It is helpful to know what exactly is going on when you are washing your hands with soap and water. Unlike alcohol-based hand sanitizers, washing your hands with soap and water does not kill pathogens, it removes them.
How does soap remove germs?
Soap and water does not kill germs; they work by mechanically removing them from your hands. Running water by itself does a decent job of pathogen removal, but soap allows you to tackle the hard to remove germs by acting like a crowbar. Soap molecules have two ends: hydrophilic, attracting water, and hydrophobic, repelling water.
First, the hydrophilic ends of the soap molecule attach to the water, then the hydrophobic ends attach to the oils, pathogens, or other debris on the hand. After the soap has bonded with the germs on your hand the water can then wash it down the drain. This works because the soap molecule can attach to the germs more strongly than the germs can hold onto your skin.
Soap is powerful, but it cannot do all the work on its own. The amount of time you are rubbing your hands together and lathering up plays a massive role in handwashing efficacy. If you scrub your hands for just 15 seconds you remove about 90% of pathogens, but with an additional 15 seconds, you are removing 99.9% of pathogens. This extra time ensures your entire hand is covered and allows the scrubbing motion to detach bacteria from your hands and be picked up by the soap and water.
Why remove pathogens when you could kill them?
The option to kill germs using a hand sanitizer seems like the best option at first glance. But there are a few things that make handwashing with soap and water superior to alcohol-based sanitizers.
Alcohol can be detrimental to skin health. The overuse of sanitizers can cause dehydrated skin much quicker than over washing of hands due to alcohol content. An important piece of hygiene is maintaining healthy, moisturized skin. Learn more about skin health and how to maintain healthy hands here.
Here at Meritech, we have designed a fully automated handwashing station that will achieve greater than 99.9% pathogen removal in less than half the time it takes to scrub your hands manually. Learn more about how CleanTech® works.