Editor’s note: In recognition of Global Handwashing Day today, we have compiled information from the CDC about why it is so important to promote this simple activity. 

Handwashing is like a “do-it-yourself” vaccine to reduce the spread of diarrheal and respiratory illness so you and those around you can stay healthy.

To watch a CDC video on handwashing techniques and why its important to get it done right, click on the image.
To watch a 3-minute CDC video on handwashing techniques and why its important to get it done right, click on the image.

Proper hand washing at the proper times could reduce diarrhea illnesses by a third and respiratory illnesses by almost a fifth according to multiple research reports.

While many of those illnesses are among residents of underdeveloped countries, many cases of norovirus and other foodborne illnesses, as well as colds and flu, in the U.S. could be avoided every day if more people practiced better hand hygiene.

Global Handwashing Day is a way to support a global and local culture of handwashing with soap, shine a spotlight on the state of handwashing in each country, and raise awareness about the benefits of handwashing with soap.

Since 2008, Global Handwashing Day has been celebrated annually on Oct. 15 worldwide. The Global Public-Private Partnership for Handwashing with Soap founded Global Handwashing Day and encourages school children, teachers and families to get involved.

Although people around the world clean their hands with water, many do not use soap because it can be less accessible in developing countries. Even when soap is available, it might be reserved primarily for laundry and bathing instead of for handwashing.

In most parts of the United States, the availability of soap and running water is not a problem, yet effective hand washing is not an automatic behavior.

For parents, child care providers and educators, the challenge of instilling this life-saving behavior can be complicated by the dreaded “Why” question when they are describing the five steps to effective handwashing. The CDC has the answers you’ve been seeking.

The what and why of the 5 steps
Global Handwashing Day Oct.15Step 1. Wet your hands with clean, running water (warm or cold), turn off the tap, and apply soap.

Why? Because hands could become recontaminated if placed in a basin of standing water that has been contaminated through previous use, clean running water should be used. However, washing with non-potable water when necessary may still improve health.

The temperature of the water does not appear to affect microbe removal; however, warmer water may cause more skin irritation and is more environmentally costly.

Turning off the faucet after wetting hands saves water, and there are few data to prove whether significant numbers of germs are transferred between hands and the faucet.

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.

Step 2. Lather your hands by rubbing them together with the soap. Be sure to lather the backs of your hands, between your fingers, and under your nails.

Why? Lathering and scrubbing hands creates friction, which helps lift dirt, grease, and microbes from skin.  Microbes are present on all surfaces of the hand, often in particularly high concentration under the nails, so the entire hand should be scrubbed.

Step 3. Scrub your hands for at least 20 seconds. Need a timer? Hum the “Happy Birthday” song from beginning to end twice.

Why? Determining the optimal length of time for handwashing is difficult because few studies about the health impacts of altering handwashing times have been done. Of those that exist, nearly all have measured reductions in overall numbers of microbes, only a small proportion of which can cause illness, and have not measured impacts on health. Solely reducing numbers of microbes on hands is not necessarily linked to better health.

The optimal length of time for handwashing is also likely to depend on many factors, including the type and amount of soil on the hands and the setting of the person washing hands.

For example, surgeons are likely to come into contact with disease-causing germs and risk spreading serious infections to vulnerable patients, so they may need to wash hands longer than a woman before she prepares her own lunch at home. Nonetheless, evidence suggests that washing hands for about 15-30 seconds removes more germs from hands than washing for shorter periods.

Step 4. Rinse your hands well under clean, running water.

Why? Soap and friction help lift dirt, grease, and microbes — including disease-causing germs — from skin so they can then be rinsed off of hands. Rinsing the soap away also minimizes skin irritation.

Because hands could become recontaminated if rinsed in a basin of standing water that has been contaminated through previous use, clean running water should be used. While some recommendations include using a paper towel to turn off the faucet after hands have been rinsed, this practice leads to increased use of water and paper towels, and there are no studies to show that it improves health.

Step 5. Dry your hands using a clean towel or air dry them.

Why? Germs can be transferred more easily to and from wet hands; therefore, hands should be dried after washing. However, the best way to dry hands remains unclear because few studies about hand drying exist, and the results of these studies conflict.

Additionally, most of these studies compare overall concentrations of microbes, not just disease-causing germs, on hands following different hand-drying methods. Nonetheless, studies suggest that using a clean towel or air drying hands are best.

When there’s no water and soap
Washing hands with soap and water is the best way to reduce the number of germs on them in most situations.

If soap and water are not available, use an alcohol-based hand sanitizer that contains at least 60% alcohol.

Alcohol-based hand sanitizers can quickly reduce the number of germs on hands in some situations, but sanitizers do not eliminate all types of germs and might not remove harmful chemicals.

Some experts suggest using hand sanitizer, followed by vigorous drying with a paper towel, followed by a second application of hand sanitizer that is allowed to air dry.

(To sign up for a free subscription to Food Safety News, click here.)