Turn off that hot water tap!

January 24th, 2014 Category: Educational Establishments Office Cleaning

How many of us immediately reach for the hot tap after using the toilet or emptying the bin? Apparently we’ve been washing our hands in the wrong way! Using hot water is unnecessary and harmful to the environment, according to a new study. 

Almost 70 per cent of us believe that hot water is more effective than cold or warm water, despite there being no actual evidence that backs this up.

Amanda Carrico, research assistant professor at Tennessee's Vanderbilt Institute for Energy and Environment University, told The European Cleaning Journal (ECJ): “It is certainly true that heat kills bacteria, but if you were to use hot water to kill them it would have to be way too hot for you to tolerate."

Ms Carrico explains that pathogens can only be killed by water at temperatures of 99°C and above, but the water we use to wash our hands never gets over 55°C. The sustained heat required to kill some germs would scald the skin. 

Her research team found that water as cold as 4.4°C is just as effective at reducing bacteria as hot water if hands are scrubbed, rinsed and dried properly. They also discovered that hot water can actually have an adverse effect on hygiene.

"Warmer water can irritate the skin and affect the protective layer on the outside, which can cause it to be less resistant to bacteria," added Ms Carrico.

The study concluded that washing hands using hot water is unnecessary and wasteful. It may seem like a trivial issue next time you visit the bathroom, but the water wasted really adds up. 

Nearly 800 billion hand washes are performed each year by just Americans, which is equivalent to six million metric tonnes of CO2 emissions annually!

Ms Carrico thinks that a water temperature should be specified in official guidelines from the Centre for Disease Control and Prevention and the World Health Organisation, which currently only recommend using soap and water and scrubbing vigorously for at least 20 seconds followed by a thorough dry.

Next time you visit the bathroom, think before you reach for the hot water tap.