While it's been debated, new research hopes to settle the argument: cold water can remove bacteria just as effectively as hot water can. Researchers followed 21 participants over a period of six months, testing length of washing and temperature of the water - 60, 79 or 100 degrees. The temperature of the water did not matter, and bacteria was significantly removed in ten seconds.
"This study may have significant implications towards water energy, since using cold water saves more energy than warm or hot water," said Donald Schaffner, a Professor and Extension Specialist in Food Science at Rutgers.
Some states view FDA guidelines as specifying a water requirement of 100 degrees, said Schaffner. "I think this study indicates that there should be a policy change," Schaffner said. "Instead of having a temperature requirement, the policy should only say that comfortable or warm water needs to be delivered. We are wasting energy to heat water to a level that is not necessary."
