Using an air dryer might feel more sanitary than paper towels, because you don’t have to actually touch anything. But apparently that couldn’t be further from the truth…
A recent study in the Journal of Applied Microbiology has compared how viruses disperse from the hands of users of three different drying methods — paper towels, standard “warm air” dryers, and so-called “jet dryers” like the Dyson model.
The lower-power warm air dryers spread contaminants further than paper towels, but the jet dryers were by far the worst culprits. They spread up to 190 times more of a noninfectious test virus used in the study than the other methods. The material was dispersed up to three meters away — nearly 10 feet—and a closer look at the study by Ars Technica found that about 70% of the dispersed material was at the height of a small child’s face.
And according to the CDC, effective handwashing takes about 20 seconds with warm water and soap. Anything short of that — say, just a quick rinse — will leave things like norovirus and influenza virus on your hands. And viruses are hardy little things — the new study found virus in the air even 15 minutes after someone used a jet dryer, at levels 100 times higher than after a paper towel was used.