Cold water ‘as good as hot’ for washing

WASHING hands with cool water is just as effective in killing germs as using hot.

Water at a cool 15°C or 60°F was as good as water at 37.7°C or 100°F and antibacterial soap was no better than normal soap, researchers found.

But whichever temperature and soap you use, you have to scrub your hands for at least 10 seconds to get rid of harmful food poisoning bacteria.

The findings by Rutgers University could not only save the planet but also improve food preparation hygiene standards.

Professor Donald S chaffner said: “People need to feel comfortable when they are washing their hands but as far as effectiveness, this study shows us the temperature of the water used didn’t matter.

“This study may have significant implications towards water energy, since using cold water saves more energy than warm or hot water.”

He added: “An antimicrobial soap formulation of one per cent chloroxylenol was not significantly more effective than the bland soap for removing E. coli under a variety of test conditions.

“Also, we learned even washing for 10 seconds significantly removed bacteria from the hands.”

He said although the literature on hand washing was extensive, it often contained conflicting data and some recommendations about water temperature were made without scientific backing.

US regulators have issued guidelines that has a requirement water temperature for handwashing must be 100°F.

Researchers daubed high levels of a harmless bacteria on the hands of two volunteers multiple times over six months before they were asked to wash their hands in either 60°F, 79°F or 100°F water using 0.5 ml, 1 ml or 2 ml of soap.