The Most Effective Way to Wash Your Hands — According to Science

By George Dvorsky on at

Keeping our hands clean is the best way to prevent the spread of infections, so it’s surprising to learn that that US Centers for Disease Control (CDC) and the World Health Organization (WHO) disagree on how to do it right. A new study shows that the six-step hand-washing technique promoted by the WHO is the better option.

Researchers from Glasgow Caledonian University have shown that the WHO’s six-step hand hygiene practice (pdf) is superior to the CDC’s three-step protocol. If you didn’t think it was possible to get really absurdly nerdy about hand washing, get ready.

In a randomised control trial, a research team led by Jacqui Reilly tracked 42 physicians and 78 nurses at an acute-care teaching hospital as they washed their hands with an alcohol-based solution. These 120 participants washed their hands using one of the two techniques (in a 50/50 split), after which time their hands were analysed for bacterial buildup.

The Most Effective Way to Wash Your Hands—According to Science

The six-step hand-washing technique. (Image: NHS).

Results showed that the six-step technique was more effective at reducing bacterial count, reducing the median microbial count from 3.28 to 2.5. By comparison the three-step technique reduced the mean bacterial count from 3.08 to 2.88.

Which, when you think about it, is hardly a surprise; the six-step method is clearly more thorough, though now there’s actual science to back it up.

However, given the added three steps, the six-step method required about 42.5 seconds of hand-washing, which is about 7.5 seconds longer than the other technique. Discouragingly, only 65 per cent of the study participants — despite having instructions — actually managed to correctly wash their hands using either protocol. (In other words, there are poopy hands everywhere.)

“The study provides the first evidence in a randomised controlled trial that the 6-step technique is superior, thus these international guidance documents should consider this evidence, as should healthcare organisations using the 3-step technique in practice,” conclude the authors in the paper, which has been published at Infection Control & Hospital Epidemiology.

It’s also definitely something to think about at home, even if an alcohol-based solution isn’t available. The same principles that apply to anti-bacterial solution apply to soap as well. [Infection Control & Hospital Epidemiology via The Telegraph]