Wash Hands Before You Eat
In a former life, I had a daycare center. As I prepared to be licensed, I remember sitting in a class where we were taught to properly wash our hands. Honestly, my eyes glazed over. Coming from a house where washing hands needed to be a nanosecond affair so we could get to the table the instant Dad was ready to eat, I could not fathom all the scrubbing and lathering, and did she say twenty seconds of washing? Then I found myself changing two dozen diapers a day, and my lathering and scrubbing became an art form.
We all know the answer to why we should wash our hands, and there are few who don’t think it is important. But the short science-y answer is: microbes. We all have millions of these microscopic living organisms on our hands. Some undetermined number of those microbes are germs, which cause disease. (1) Washing hands helps remove germs and other microbes so we can prevent ourselves from getting communicable diseases like the common cold, meningitis, the flu, hepatitis A and infectious diarrhea, among many other things we would rather not have, ever. (2)
According to the Centers for Disease Control and Prevention (CDC), we should wash our hands:
- Before, during, and after preparing food
- Before eating food
- Before and after caring for someone who is sick
- Before and after treating a cut or wound
- After using the toilet
- After changing diapers or cleaning up a child who has used the toilet
- After blowing your nose, coughing, or sneezing
- After touching an animal, animal feed, or animal waste
- After handling pet food or pet treats
- After touching garbage (3)
Most health websites agree that there are five steps to properly wash hands. Here they are, with a little elaboration on the science behind the steps:
Wet the hands with clean, running water. Turn off the tap (to save water) and apply soap.
Running water to wet the hands is better than standing water in a basin, according to the CDC, as standing water may have been contaminated with previous washing. Soap has been proven to be more effective than water alone to remove germs. (4)
Lather up thoroughly, including backs of hands, wrists, between fingers and under fingernails.
Microbes are all over the hand, with higher concentrations under nails. (5)
Scrub all of the aforementioned parts for at least 20 seconds. Singing “Happy Birthday” twice takes roughly 20 seconds if a timer is not handy.
Scrubbing thoroughly for between 15-30 seconds removes more germs than shorter scrubbing sessions. (6)
Rinse hands well under running water.
Soap and scrubbing dislodge microbes; rinsing is now needed to wash them down the drain. Once again, running water is better than water standing in a basin. (1)
Dry hands with a clean towel or air dry them.
Germs transfer more easily when hands are wet rather than dry. (7)
(Primary source CDC website: http://www.cdc.gov/handwashing/show-me-the-science-handwashing.html)
Handwashing ins and outs from the CDC:
..and the Mayo Clinic:
From the newsroom: “Hidden Germs: What Lurks on Your Hands”
- “Show Me the Science – How to Wash Your Hands,” Centers for Disease Control and Prevention, website accessed 18 Aug 2016. http://www.cdc.gov/handwashing/show-me-the-science-handwashing.html
- “Why is Hand Washing So Important?” KidsHealth, website accessed 18 Aug 2016. http://kidshealth.org/en/parents/hand-washing.html
- “When & How to Wash Your Hands,” Centers for Disease Control and Prevention, website accessed 18 Aug 2016. http://www.cdc.gov/handwashing/when-how-handwashing.html
- Luby SP, Halder AK, Huda T, Unicomb L, Johnston RB. The effect of handwashing at recommended times with water alone and with soap on child diarrhea in rural Bangladesh: an observational study. PLoS Med. 2011 Jun;8(6):e1001052.
- Lin CM, Wu FM, Kim HK, Doyle MP, Michael BS, Williams LK. A comparison of hand washing techniques to remove Escherichia coli and caliciviruses under natural or artificial fingernails. J Food Prot. 2003 Dec;66(12):2296-301.
- Jensen D, Schaffner D, Danyluk M, Harris L. Efficacy of handwashing duration and drying methods. Int Assn Food Prot. 2012 July.
- 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.