According to a newly published study, it seems that rubbing your hands together in a hand dryer actually leaves them coated with more bacteria than immediately after washing.

“When you rub your hands, you bring a lot of bacteria to the surface from the pores of your skin,” says Anna Snelling of the University of Bradford, UK. Snelling conducted the research with 14 volunteers, on three different types of air dryers, instructing each volunteer to use the air dryer for 15 seconds. On each model, the volunteer had to rub their hands while drying, while on the second try they would just hold their hands still.

The study revealed that when volunteers kept their hands still, the dryers reduced skin bacteria numbers by around 37% compared to just after washing. But the count rose by 18%when volunteers rubbed their hands under one of the machines. Paper towels proved the most efficient, halving the bacterial count even though volunteers rubbed their hands, so if you do happen to use an air dryer consider scrubbing your hands with a paper towel, especially if you’re around sick people. [link to study]