A study from microbiologists at the University of Westminster has confirmed that if you’ve been using a hand dryer after washing your hands, you’ve been doing it all wrong.

Paper towels are officially the most hygienic way to dry your hands.

In tests, jet air dryers caused the greatest spread of microbes. The electric dryer fired up to 59.5 yeast colonies (as used for the test) into the air, while the humble paper towel released just 2.2.

"These findings clearly indicate that single-use towels spread the fewest microbes of all hand-drying methods,” leading researcher Keith Redway explained.

Mind you, ‘fewest’ microbes may still be too many. After all, the average person's hands carry at least 3,000 different bacteria – with a quarter carrying a trace of faeces.

“A third of average public washroom exposed surfaces will be contaminated with coli-form bacteria,” says Brian Dewsbery, of Sterillo hand-dryers - the only ones proven to actually kill airborne microbes. “This makes it near impossible for anyone to wash and dry their hands without being contaminated.”

He adds that the infections that can be spread as a result include Salmonella, E-Coli, MRSA, Hepatitis A.

Ironically, “one of the most contaminated areas in the washroom are the taps and sink where you ‘clean’ your hands.

“Regardless of how someone dries their hands, as soon as they touch any of the washroom surfaces or the door handle to exit the washroom they are almost certainly re-contaminating themselves. The only solution to clean hands in public washrooms is to sanitise the entire environment by cleaning all the air and all the surfaces.”

Bearing in mind your average public toilet facility is unlikely to do that, here’s how to clean (and dry) yours hands as best you can.

The 30-second rule

“It is best to wash your hands with hot water for at least 30 seconds, but many washrooms have cold water - and soap isn’t always available,” says Dewsbery.

In a hurry? A simple timing trick is that washing your hands with hot water and soap should last for at least the time it takes to sing a verse of Happy Birthday.

Follow the order

According to the Global Hygiene Council, you need to adhere to a strict plan for effective hand washing. Wet hands first, then apply the soap - not the other way around.

Rub

The rubbing system goes like this: rub palms together until soap is bubbly, then rub each palm over the back of the other hand - then rub between your fingers on each hand.

And keep on rubbing

Then it’s the backs of fingers (when they’re interlocked), around each of your thumbs, then both palms together again. The government’s guidelines also include (some complicated-sounding) “Rotational rubbing of left thumb clasped in right palm, and vice versa” as well as “Rotational rubbing, backwards and forwards with clasped fingers of right hand in left palm, and vice versa.’

Rinse and dry

Rinse with water, and then you can dry off - with a paper towel, of course.

Then turn off the tap

Don’t fall at the final hygiene hurdle. Turn off the tap not when you’ve finished washing your hands, but after you’ve dried them. Turn off the tap with a paper towel in hand - after all, a washroom tap boasts 35% contamination.

One more tip: be a woman

“Our recent research revealed that 30% of men sometimes don’t wash their hands at all,” says Dewsbery.