Faced with soaring energy prices, many of us are trying to save electricity through small gestures: doing the laundry during off-peak hours, turning off the lights when they are not needed, taking shorter showers…
To lighten the electric bill a little, taking your foot off the hot water can also be a good idea. But then a fundamental question arises: is washing your hands with cold water really effective in killing germs?
Hot water or cold water, the efficiency is the same!
Researchers from Rutgers University-New Brunswick (in the United States) have looked into the matter. To do this, they covered the hands of 21 volunteers with bacteria that were not dangerous to health; then participants had to wash their hands with soap and water at either 15 degrees, 26 degrees, or 38 degrees. The experiment was repeated several times over a period of 6 months.
Result ? The American researchers are formal: the temperature of the water has absolutely no importance when it comes to getting rid of microbes. On the other hand, to kill bacteria and have perfect hygiene, it is necessary to wash your hands for at least 10 seconds (not easy when the water is freezing!) and with at least 0.5 mL of soap – the equivalent of a small amount of liquid soap.
“If you tolerate contact with cold water well, it is therefore not necessary to wash your hands in hot water: it saves energy!“the scientists point out.
Source : Rutgers University-New Brunswick
