Five Things You Might Not Know About Washing Your Hands

Keeping your hands clean is one of the most important steps you can take to avoid getting sick and spreading germs to the people around you. Many diseases and conditions are spread by not cleaning your hands properly. Here are five important things you might not know about washing your hands and why it matters.

1. Soap is key. Washing your hands with soap removes germs much more effectively than using water alone.[i] The compounds, called surfactants, in soap help remove soil and microbes from your skin. You also tend to scrub your hands more thoroughly when you use soap, which also helps to removes germs.

2. It takes longer than you might think. The optimal length of time to wash your hands depends on many factors, including the type and amount of soil on your hands. Evidence suggests that washing your hands for about 15–30 seconds removes more germs than washing for shorter periods.[iii] CDC recommends washing your hands for about 20 seconds, or the time it takes to hum the “Happy Birthday” song twice from beginning to end.

3. It’s all about technique. Make sure to clean the spots on your hands that people miss most frequently. Pay particular attention to the backs of your hands, in between your fingers, and under your nails. Lathering and scrubbing your hands creates friction, which helps to remove dirt, grease, and germs from your skin.

4. Don’t forget to dry. Germs can be transferred more easily to and from wet hands, so you should dry your hands after washing.[iv] Studies suggest that using a clean towel or letting your hands air dry are the best methods to get your hands dry.[v],[vi],[vii]

5. Hand sanitizer is an option. If you can’t get to a sink to wash your hands with soap and water, use an alcohol-based hand sanitizer that contains at least 60% alcohol. Make sure you use enough to cover all surfaces of your hands. Do not rinse or wipe off the hand sanitizer before it is dry.[viii]

Note: Hand sanitizer may not kill all germs, especially if your hands are visibly dirty or greasy,[ix] so it is important to wash hands with soap and water as soon as possible after using hand sanitizer.

Why it Matters

Remember, clean hands save lives. Diarrheal diseases and pneumonia are the top two killers of young children around the world, killing 1.8 million children under the age of five every year.[x] Among young children, handwashing with soap prevents 1 out of every 3 diarrheal illnesses [xi] and 1 out of 5 respiratory infections like pneumonia worldwide.[xii],[xiii]

October 15^th is Global Handwashing Day

Handwashing is for everyone…everywhere. Global Handwashing Day is an opportunity to support a global and local culture of handwashing with soap and water, shine a spotlight on the state of handwashing in each country, and raise awareness about the benefits of washing your hands with soap. Although people around the world clean their hands with water, very few use soap to wash their hands because soap and water for handwashing might be less accessible in developing countries.

Get Involved!

• Organize or participate in a handwashing event in your school or community. Find educational resources and materials and planning tools.
• Celebrate virtually on Twitter and Facebook. Look for and use the hashtag #GlobalHandwashingDay, download pre-drafted educational social media messages, and share CDC’s Global Handwashing Day digital button.
• Make sure you and your family know when and how to wash your hands properly.
• Share the science behind handwashing.

References

[i] Burton M, Cobb E, Donachie P, Judah G, Curtis V, Schmidt WP. The effect of handwashing with water or soap on bacterial contamination of hands. Int J Environ Res Public Health. 2011 Jan;8(1):97-104.

[ii] Burton M, Cobb E, Donachie P, Judah G, Curtis V, Schmidt WP. The effect of handwashing with water or soap on bacterial contamination of hands. Int J Environ Res Public Health. 2011 Jan;8(1):97-104.

[iii] Jensen D, Schaffner D, Danyluk M, Harris L. Efficacy of handwashing duration and drying methods. Int Assn Food Prot. 2012 July.

[iv] Patrick DR, Findon G, Miller TE. Residual moisture determines the level of touch-contact-associated bacterial transfer following hand washing. Epidemiol Infect. 1997 Dec;119(3):319-25.

[v] Gustafson DR, Vetter EA, Larson DR, Ilstrup DM, Maker MD, Thompson RL, Cockerill FR 3rd. Effects of 4 hand-drying methods for removing bacteria from washed hands: a randomized trial. Mayo Clin Proc. 2000 Jul;75(7):705-8.

[vi] Huang C, Ma W, Stack S. The hygienic efficacy of different hand-drying methods: a review of the evidence. Mayo Clin Proc. 2012 Aug;87(8):791-8.

[vii] Jensen D, Schaffner D, Danyluk M, Harris L. Efficacy of handwashing duration and drying methods. Int Assn Food Prot Annual Meeting. 2012 July 22-25.

[viii] Widmer, A. F., Dangel, M., & RN. (2007). Introducing alcohol-based hand rub for hand hygiene: the critical need for training. Infection Control and Hospital Epidemiology, 28(1), 50-54.

[ix] Pickering AJ, Davis J, Boehm AB. Efficacy of alcohol-based hand sanitizer on hands soiled with dirt and cooking oil. J Water Health. 2011 Sep;9(3):429-33.

[x] Liu L, Johnson HL, Cousens S, Perin J, Scott S, Lawn JE, Rudan I, Campbell H, Cibulskis R, Li M, Mathers C, Black RE; Child Health Epidemiology Reference Group of WHO and UNICEF. Global, regional, and national causes of child mortality: an updated systematic analysis for 2010 with time trends since 2000. Lancet. 2012 Jun 9;379(9832):2151-61.

[xi] Ejemot RI, Ehiri JE, Meremikwu MM, Critchley JA. Hand washing for preventing diarrhoea. Cochrane Database Syst Rev. 2008;1:CD004265.

[xii] Rabie T and Curtis V. Handwashing and risk of respiratory infections: a quantitative systematic review.Trop Med Int Health. 2006 Mar;11(3):258-67.

[xiii] Aiello AE, Coulborn RM, Perez V, Larson EL. Effect of hand hygiene on infectious disease risk in the community setting: a meta-analysis. Am J Public Health. 2008;98(8):1372-81.