Washing your hands is a surefire way to rinse away potentially hostile microbes. But is there a single best way to do it?

That's what a team of UK-based researchers tried to figure out in a study published this month in the journal Infection Control & Hospital Epidemiology. The team compared two different hand-washing methods: a six-step method from the World Health Organisation and a three-step method from the US Centres for Disease Control and Prevention.

The difference came down to the parts of the hands that are scrubbed. The three-step method details applying an "alcohol-based handrub" (a type of hand sanitiser that can be used instead of soap) to the palm and rubbing hands together, applying the rub to all surfaces, then continuing to do it until the hands are dry.

The six-step method covers six different parts of the hand, going from palm-to-palm, rubbing the thumbs, and getting in between the fingers, using either soap or an alcohol-based handrub. The six-step method takes on average 42.5 seconds while the three-step method takes 35 seconds.

Washing hands, especially in a hospital setting, is key for keeping infections down. To see which one was more effective, researchers from the UK observed the hand-washing habits of 42 doctors and 78 nurses at a hospital in Glasgow, Scotland. Half were assigned to do the three-step method, while the other had to do the six-step method.

After they interacted with patients, the researchers then collected a sample from the doctor or nurses' hands to check for bacterial counts, and found that the six-step method from the WHO reduced the bacterial count more than the three-step method.

They found that the bacterial count for those who did the six steps was down about 21 percent, while those who did the three steps had a 6 percent reduction.

Want to be sure you're doing it right? Follow these steps, courtesy of the WHO:

  • Wet hands with water
  • Grab enough soap to cover all surfaces of your hands
  • Rub palm-to-palm
  • Rub your right palm over the back of your left hand, interlacing fingers, then do the reverse
  • Rub your hands palm-to-palm with interlaced fingers
  • Rub the backs of your fingers against the opposite palm so that your hands are interlocked
  • Rub your left thumb in your right palm, and then do the reverse
  • Get your fingertips in there too, by rubbing your right-hand fingers against your left palm, then doing the reverse
  • Rinse, dry, and you're done!

This article was originally published by Business Insider.

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