A new study looking at washing your hands has come up with some interesting findings, or at least some interesting suggestions that may need further investigation as the sample for the study was small – 20 people, 10 men and 10 women.

The study was carried out by researchers from Rutgers University and GOJO Industries in the US.

It is worth noting GOJO Industries produce hand sanitisers and soaps yet the research suggests these are of no more benefit than regular soap and water and cold water is just as effective as how water. What can make a difference is how long you wash your hands for.

The research only tested for E. coli bacteria which is a leading cause of food poisoning. They found using cold was just as effective at getting rid of the bacteria as washing with hot water and antibacterial handwash or soap was not significantly more effective at removing the bacteria than normal soap.

It did establish that washing your hands for longer – 30 seconds instead of 15 seconds – is more effective at getting rid of bacteria if you want to protect yourself against food poisoning or infections like the flu.

It has to be said that the research only compared two products and also only studied E. coli.

There would need to be further, more in-depth research covering a wider range of products and other types of bacteria and infections before it can be stated for certain that cold water is just as effective as hot.

Using an antimicrobial soap wasn’t found to be significantly more effective than normal soap at removing bacteria during any of the trial washes. There was no significant reduction in bacteria after handwashing between the lowest and highest water temperatures of 15C or 38C.

Washing for 30 seconds (20 seconds of lathering and 10 seconds rinsing off) was found to notably reduce bacteria compared with washing for 15 seconds (10 seconds of lathering and 5 seconds rinsing off) when using common soap. Lather time didn’t affect bacterial count for antimicrobial soap.

Current guidelines recommend that we wash our hands with water and soap for at least 20 seconds:

after using the toilet

after handling raw foods like meat, fish and vegetables

before eating

after touching pets or animals