A little-known danger in public toilets: why should we avoid hand dryers?

Since the Covid-19 pandemic, we all know that washing your hands is the first barrier gesture to avoid germs. But wet hands increase the risk of transmitting bacteria. Drying is therefore an equally important prevention step.

The professionals understand this well. In the toilets of supermarkets, airports or other cinemas… electric air hand dryers have almost become the norm. But do they really guarantee safety against germs and viruses?

Not so sure. In fact, plenty of research has shown that hot air hand dryers in public restrooms could suck bacteria from the surrounding air and release it onto the freshly washed hands of unsuspecting customers.

More than 200 colonies of bacteria

Let us cite a 2021 work carried out by scientists from the University of Cambridge (Great Britain). Volunteers were asked to wear aprons when washing and drying their hands. Half of the participants used a forced-air hand dryer while the other half used paper towels.

As a result, hand dryer users found themselves with more bacteria than expected on their hands.

Same story for a study carried out three years earlier, but in the United States this time (University of Connecticut). Researchers exposed – for 30 seconds – Petri dishes (transparent cylindrical dishes used in laboratories) to hot air from hand dryers. A spectacular experiment which saw the birth of 254 colonies of bacteria inside these small boxes.

A word of advice: it is sometimes preferable to favor traditional techniques over cutting-edge technologies. “Drying your hands with paper towels not only dries them faster, but the friction also dislodges bacteria to leave them cleaner,” notes the Cleveland Clinic on its website.

As for cloth napkin dispensers? Better to avoid them. The piece of cloth at the end of the roll tends to be reused over and over again. This again encourages the transmission of germs from hand to hand.