OK, the study results sound promising: that washing with cold water is as good as washing with warm or hot water for removing bacteria from the hands. And that type of soap didn't matter - both the anti-microbial soap and ordinary soap were equally effective. But...the researchers only looked at one strain of bacteria - E. coli (full name Escherichia coli (ATCC 11229)), and there are MANY microbes and viruses out there that cause problems. So I would view it as a nice start ( a preliminary study), but not the final word. From Science Daily:
We all know that washing our hands can keep us from spreading germs and getting sick. But a new Rutgers-New Brunswick study found that cool water removes the same amount of harmful bacteria as hot. ....In the Rutgers study, published in the June issue of the Journal of Food Protection, high levels of a harmless bacteria were put on the hands of 21 participants multiple times over a six-month period before they were asked to wash their hands in 60-degree, 79-degree or 100-degree water temperatures using 0.5 ml, 1 ml or 2 ml volumes of soap.
"Also we learned even washing for 10 seconds significantly removed bacteria from the hands." While the study indicates that there is no difference between the amount of soap used, more work needs to be done to understand exactly how much and what type of soap is needed to remove harmful microbes from hands, said co-author Jim Arbogast, vice president of Hygiene Sciences and Public Health Advancements for GOJO. "This is important because the biggest public health need is to increase handwashing or hand sanitizing by food service workers and the public before eating, preparing food and after using the restroom," Arbogast said.
These findings are significant, particularly to the restaurant and food industry, because the U.S. Food and Drug Administration issues guidelines, every four years, to states. Those guidelines currently recommend that plumbing systems at food establishments and restaurants deliver water at 100 degrees Fahrenheit for handwashing.
Schaffner said the issue of water temperature has been debated for a number of years without enough science to back-up any recommendation to change the policy guidelines or provide proof that water temperature makes a difference in hand hygiene. Many states, in fact, interpret the FDA guidelines as a requirement that water temperature for handwashing must be 100 degrees, he said. [Original study.]