How to Properly Use Hand Sanitizer

Alcohol-based hand sanitizer (ABHS) is easy to find and simple to use. To make sure it's effective, you'll need to use it correctly. You'll also need to know when it may not be the best choice.

Hand sanitizer kills many, but not all, microbes. It isn't a good way to clean chemicals off your hands, though.

This article explains how hand sanitizer works. It also describes how to use it properly and when washing with soap and water is better.

The CDC says you should wash your hands with soap and water whenever possible. It's important to use soap and water when there's dirt, grime, or something else you can see on your hands.

Hand sanitizer can be used after a soap and water wash. It can also be used when washing isn't an option.

How It Works

The active ingredient in most ABHS is either:

• Isopropyl alcohol (rubbing alcohol)
• Ethanol
• N-propanol
• A combination of them

To understand how these products kill germs, it's good to know a bit about the germs. Bacteria are one-celled living things. A cell wall surrounds their genetic material.

Viruses aren't considered living things because they need a host to survive. Many viruses have an outer envelope made of fat and protein. That layer protects their genetic material.

Alcohol dissolves the outer layer or cell wall. Once they break down, microbes can't reproduce or survive.

Hand sanitizers don't kill everything. For example, they are not as effective on viruses that don't have an outer layer.

Soap and water destroy some "bugs" that hand sanitizers don't, such as:

• Cryptosporidium, a parasite
• Clostridium difficile bacteria
• Norovirus, which causes gastroenteritis or "stomach flu"

What It Can't Promise

The FDA has taken legal action against some companies for claiming their products kill specific germs, such as:

• Salmonella
• E. Coli
• Ebola
• Rotavirus
• The flu virus
• MRSA (methicillin-resistant Staphylococcus aureus).

The companies that make these products have yet to gain FDA approval for these uses. Still, there is some evidence that they can protect you from many infections.

For example:

• A 2019 study shows they may help slow the spread of MRSA and other infections in hospitals by giving workers a quick and easy way to clean their hands.
• Research published in 2015 said that ABHS reduced salmonella and E. coli.
• Hand sanitizer used in Japan during a flu pandemic may have reduced norovirus.
• A 2018 study on daycare centers found a drop in days missed due to illness when the center provided hand sanitizers. The center also taught staff, children, and parents how to use them.
• A 2020 research review found that ABHS was effective against SARS-CoV-2, the virus that causes COVID-19.

Sometimes the results are mixed. A 2019 research review found that in some community settings, using hand sanitizer didn't always slow the spread of the flu virus.

Another 2019 study noted that an ABHS reduced norovirus infection risk by 85% when people had short-term contact with the virus. However, in situations where people have more contact with viruses, such as on a cruise ship or in a long-term care facility, the sanitizer did not protect them as well.

What to Look For

The CDC recommends products with at least 60% alcohol. Most contain between 60% and 95%. Higher alcohol content doesn't make the product more effective. To work well, these products also need to contain some water.

Some products claim to sanitize your hands but have little or no alcohol. These products will not protect you as well.

How to Use It

Hand sanitizer is effective when it's made with the right ingredients and when people use it properly. It's important to know:

• How much to use
• How to use it
• When to use it

Hand sanitizer can be a good option when:

• You're riding public transportation
• You have shaken hands with someone
• You've touched an animal
• You've touched a grocery cart or another surface used by others
• You're somewhere without soap and water

To use hand sanitizer correctly:

• Place plenty of the product in the palm of one hand. The CDC recommends that you use enough to cover your whole hand.
• Rub your hands together. Make sure to include the spaces between your fingers.
• Stop rubbing only when your skin is dry. Don't wipe off the excess.

When Not to Use It

Don't use hand sanitizer instead of soap and water when:

• You have soap and water available
• Your hands are greasy or dirty
• You have chemicals on your hands
• You may have been exposed to germs that aren't killed by hand sanitizer
• You're in a high-infection situation

To keep yourself and your family healthy, it's important to clean your hands after you've used the restroom. You should also clean them before and after you prepare food. Vigorously washing your hands with warm water and soap for 20 seconds is best.

Summary

Washing your hands is an excellent way to prevent the spread of infection. Using an alcohol-based hand sanitizer is a good option if you can't wash with soap and water.

These products work by damaging the protective layer around microbes so they can't survive. They won't kill every germ you encounter, and they won't clean dirt, grease, or chemicals off your skin.

To use hand sanitizer, start with enough product to cover your whole hand. Rub it in until your skin is totally dry. Opt for a 20-second scrub with soap and water whenever you can, because this method is usually more effective than using a hand sanitizer.

The information in this article is current as of the date listed, which means newer information may be available when you read this. For the most recent updates on COVID-19, visit our coronavirus news page.