"We learned even washing for 10 seconds significantly removed bacteria from the hands", said Schaffner (who past year proved that the five-second rule isn't real and food dropped on the floor isn't safe to eat, dang).
"Water works as a physical cleanser and washes the organisms and microbes off the hands", said Dr. Raymond Pontzer, director of infection prevention for UPMC in Pittsburgh, who was not involved in the study. They also found that lathering hands for just 10 seconds was sufficient to remove germs.
Schaffner says these findings are significant, especially when it comes to water usage and conservation as using cold water tends to save more energy than warm or hot water.
"This is important because the biggest public health need is to increase handwashing or hand sanitizing by foodservice workers and the public before eating, preparing food and after using the restroom", says Jim Arbogast, study co-author and vice president of hygiene sciences and public health advancements for GOJO.
The amount of soap used did not affect the results, but the researchers believe that more research could be useful to establish the optimal type and amount of soap that reduces bacterial loads.
"People need to feel comfortable when they are washing their hands but as far as effectiveness, this study shows us that the temperature of the water used didn't matter", said Professor Donald Schaffner, a Rutgers specialist in food science, in a statement. But a new Rutgers-New Brunswick study found that cool water removes the same amount of harmful bacteria as hot.
The team tested 21 volunteers who had their hands exposed to harmless bacteria and who washed at various temperatures over a six-month period.
They also said that using antibacterial soap instead of normal soap didn't make much difference either.
They were then 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.
The scientists say their findings should lead to a change in US Food and Drug Administration guidance on hand washing.
Do you use hot or cold water when you wash your hands?
Antibacterial soap was more effective than ordinary soap, the study finds. "Does it give us the definitive answer about hand washing?"
Scrub all surfaces of the hands.
Often we get advised to use warm water, because it's thought to be better at getting rid of germs. The authors of the study hope that the agency will revise water temperature policy at that time to avoid so much wasted energy on hot water usage.