How Do Hand Soaps and Hand Sanitizers Work?

Hand Soaps and hand sanitizers have established themselves as everyday public health solutions around the home and on the go—and rightfully so. Your hands often touch more surfaces from day to day than all other parts of your body combined, allowing plenty of opportunities to pick up stray bacteria as they do. All it takes is an eye rub or face scratch to give those germs an all-access pass inside your body. Soap and sanitizer are efficient at eliminating the threat altogether by killing the germs on your hands before they get a chance to cause real problems.

Doesn’t rinsing with water clean your hands? A little, but not particularly well. A study conducted in 2011 found that washing hands with only running water reduced the presence of bacteria on the skin to 23%. Meanwhile, rinsing with a combination of water and hand soap took the germ presence down to only 8% for clean hands. Water is better than nothing, but still leaves a fair amount of foreign invaders and infectious diseases in your palms.

But how does soap work so well, and how is soap different than sanitizer? How well does hand sanitizer work? Let’s take a look under the microscope and see what’s really going on when it comes to hand hygiene!

How Does Hand Soap Kill Germs?

On the molecular level, the suds you produce from washing your hands with soap act as lethal assassins ready to disrupt any pathogens which might be clinging to the skin. Many (but not all) viruses and bacteria surround themselves in a cell wall consisting of fats and lipids that help protect the invader from other foreign bodies it encounters. These bacteria are called Acid-fast bacteria and are common in the microscopic world. The infamous coronavirus is acid-fast with multiple layers of fats along with protein spikes.

Now let’s examine your soap. Soap molecules are made of two primary components which react to water differently: a “head” which is hydrophilic (meaning it is attracted to water) and a long “tail” put together by hydrogen and carbon atoms which is hydrophobic (meaning it repels water). After being dissolved in your running faucet water, bundles of these plain soap molecules come together and form spherical patterns called micelles. In these formations, the hydrophilic heads face outside the cluster while the hydrophobic tails face inside.

Remember how our bacteria contains layers of fats that serve as a protective barrier? The inside of soapy micelles becomes perfect for breaking down fats with all of the hydrophobic tails working together inside the cluster. Not only that, but the fatty sheath around the bacteria is also hydrophobic, meaning it is easily trapped in the hydrophobic cores of micelles. The micelles then take down the bacteria’s cell wall, exposing the bacterium itself and killing it. Running water (combined with friction from drying your hands with a paper towel or cloth) then removes the dead bacteria particles off your skin. This makes hand soap an extremely strong counter measurement against the novel coronavirus pandemic!

How Does Hand Sanitizer Kill Bacteria?

Hand sanitizer functions differently compared to classic hand soap and water. Unlike most soaps, sanitizer’s key ingredient involves alcohol—typically ethyl alcohol (ethanol)or isopropyl alcohol (isopropanol), which are both easily soluble in water. Rather than break down the fats in bacteria cell walls, hand sanitizer directly attacks the protein spikes found within the germs, killing them directly by splitting them into fragments. Hand sanitizer does not, however, remove the leftovers from your skin, meaning wiping your hands with a clean towel afterward is still beneficial.

Medical alcohol can be effective at disabling bacteria at as little as 30 percent alcohol concentration in your sanitizer. Nevertheless, studies have shown that solutions with 60 to 80% alcohol content are the best for dealing with a wide range of pathogens that might be tougher to breach. Any higher and the efficacy is negligible for most strains of bacteria. In fact, ethyl alcohol is actually better at taking down several select types of germs (Escherichia coli, Staphylococcus saprophyticus, and Serratia marcescens) compared to traditional hand soap washing.

Despite its usefulness and convenience on-the-go, sanitizer lathering still has its drawbacks. Namely, hand sanitizer does not remove specific strains of germs (norovirus in particular), harmful chemicals like pesticides, heavy metals, and dirt and grease stains left behind on the surfaces of your hands. For those cases, washing with water and soap is still the best option. Most professionals recommend hand sanitizer is best used alongside regular hand washing as opposed to replacing it.

The Centers for Disease Control and Prevention (CDC) recommends the use of hand sanitizers with at least 60% alcohol content in order to remove the most germs. Certain formulas make do without any alcohol at all, but according to the CDC they may not kill as many germs, slowing down the flourishing of bacteria instead.

Can Hand Sanitizer or Hand Soap Ever Expire?

Although many hand soap and sanitizer manufacturers will set expiration dates on their products, most solutions will never expire. The date on the label is supposed to indicate how long the serum’s active ingredients and alcohol concentration will last as determined by testing. The Food and Drug Administration (FDA) requires certain information such as expiration dates to be listed on regulated health and wellness packaging. Although it is often unknown to consumers whether or not companies actually perform the testing, rest assured alcohol solutions will remain concentrated at room temperatures for many, many years.

Use the Only the Best!

Based on its behavior, hand washing with water and soap is still the most effective method to clean your hands. But in cases where you’re in a hurry or a sink isn’t available, hand sanitizer can get the job done and give you peace of mind until you find some hand soap. The problem with most hand sanitizers? The alcohol strips away the outer oils of your hands, leaving them dry and irritated after too much use.

That’s why Muse Health’s Fragrance-free Hand Sanitizer includes natural healing lotions in addition to enough ethyl alcohol to kill 99% of germs. That means your hands stay smooth, soft, and healthy even after multiple uses. Visit our shop to learn more when you need to use hand sanitizer on the go!