It’s hard to go into most public bathrooms these days and not see a hand dryer attached to the wall. Air dryers are being utilized in public bathrooms as a way of reducing paper waste, but are they a better method for drying your hands than paper towels?
Some studies show that hand dryers are actually blowing more bacteria onto our hands rather than getting rid of it. According to a study from the Mayo Clinic Proceedings that compares the hygiene efficiency of different hand-drying methods, a paper towel dries hands more efficiently and removes more bacteria from your hands. Researchers found that hot and jet air dryers could increase most types of bacteria on your hands.
The reason for this stems from the bacteria that forms in the air of public restrooms. Every time a lidless toilet is flushed, microbes of bacteria form in the air and can spread over an area as large as 6 square meters, according to Harvard Medical School. Researchers suspect that the bacteria gets sucked up by the air dryers and stays in the machine’s nozzle until it is turned on, spreading germs onto washed hands.
Scientists have conducted tests of these theories using plates that collect bacteria. When exposed to hot air from the hand dryer for 30 seconds, most of the plates grew between 18 and 60 colonies of bacteria, with one growing 254 bacterial colonies. This was compared to the plates that weren’t exposed to the hand dryer, which grew only one or no colonies at all.
However, according to Paul Suits, director of Infection Control at Upstate Medical University, hand dryers are safe to use. “Most people aren’t going to get sick [from hand dryers] because most people are healthy. So it’s not an issue,” Suits said.
Suits further explained that people should be more concerned about the germs that stay on their hands from not drying their hands properly. “If you don’t completely dry your hands, it won’t kill all of the bacteria.”
Suits recommends paper towels over hand dryers, but only because they can be used to open the door when leaving the bathroom. “You can recontaminate your hands with bacteria on the doorknob from other people who didn’t wash their hands.”
It’s no secret public restrooms are brimming with bacteria, and washing your hands is just one of the many daily habits that might keep you from getting sick.