Friend of the blog Don Schaffner of Rutgers University tells the Academic Minute (in a quite professorial tone) that washing keeps bacteria and other pathogens at bay and all research suggests that keeping clean is a good thing, but handwashing is an inexact process.

Dr. Donald W. Schaffner is Extension Specialist in Food Science and Distinguished Professor at Rutgers University. Dr. Schaffner has authored more than 100 peer-reviewed publications, book chapters and abstracts. Dr. Schaffner has educated thousands of Food Industry professionals through numerous short courses and workshops in the United States and more than a dozen countries around the world. Dr. Schaffner was elected a Fellow of the IFT in 2010 and AAM in 2013 and is an Editor for the ASM journal Applied and Environmental Microbiology. Dr. Schaffner is the president of the IAFP 2013-2014.

You’ve probably heard all of your life that hand washing is important to public health.

In fact, the published research supports this quite strongly. Numerous scientific research articles show the positive impact on a variety of target populations when hand washing is encouraged, or in developing countries when something as simple as a bar of soap is provided to people that could not previously afford it.

You may have even heard advice about washing your hands: Things like “wash your hands for 20 seconds”, or you may have heard the same phrase, with 15 seconds or 30 seconds being the recommended time frame. The United States Centers for Disease Control and Prevention (the CDC) recommends teaching your child to wash their hands for as long as it takes to sing the “happy birthday” song twice (approximately 20 seconds).

You might be surprised to learn however, that the scientific basis for 5, 10, 15, 20, or even 30 seconds is virtually nonexistent. Research is currently underway in our lab to better characterize the effect of wash time, as well as other parameters on the effectiveness of a good hand wash. We are quantifying the effect of soap versus no soap, antibacterial versus plain soap, the effect of water temperature, the optimum wash time, and the method of drying.

 So, wash your hands! Especially after handling raw meat, changing a dirty diaper, or after you poop. How long should you wash your hands?

We’re working on it.