Scientists have poured cold water on the theory that we need to wash our hands with hot water to kill germs.
'This study may have significant implications towards water energy, since using cold water saves more energy than warm or hot water'. The researchers from Rutgers University published their findings in the Journal of Food Protection.
Antibacterial soap was more effective than ordinary soap, the study finds.
The team tested 21 volunteers who had their hands exposed to harmless bacteria and who washed at various temperatures over a six-month period.
The findings are in line with United Kingdom and worldwide advice that washing your hands with soap in either warm or cold water amounts to good protection from food poisoning, colds and flu. The researchers put a non-virulent strain of E. coli on each person's hand prior to the cleansing to measure how the techniques worked.
The time of ten seconds stayed constant in each of the cases.
He also points out that this is the minimum amount of time the authors are recommending for hand washing-and that some circumstances may call for longer washes. It emphasizes that hands should be washed and rubbed vigorously for at least 20 seconds - as long as singing "Happy Birthday" twice, and that enough soap should be used to cover the whole surface of both hands.
Handwashing is a hot topic in the world of food safety.
'But the actual water temp won't kill bacteria as it can't be too hot or it would burn'.
They discovered washing in cool water removes just as many germs as hot water. The most basic but popular assumption was challenged: 100 degrees Fahrenheit water, 1 milliliter of non-antimicrobial (bland) soap, and 5-second lather time. While many people assume warmer temperatures get rid of more germs, the researchers' results proved that it's a myth.
Professor Schaffner added: 'I think this study indicates that there should be a policy change.
Schaffner said there should not be "a temperature requirement". Schaffner said: "The policy should only say that comfortable or warm water needs to be delivered". If cold water handwashing becomes the norm, businesses could save significantly in terms of energy use. "Many hand-washing recommendations are being made without scientific backing, and agreement among these recommendations is limited, as indicated by the major inconsistencies among hand-washing signs".