For the longest time, technology stayed out of the public restroom. That is, until growing environmental and health concerns displaced non-threatening paper towel dispensers for annoying warm-air hand dryers that make folks feel like they're standing in the middle of an airport runway at rush hour when using them. But do those "wind-tunnel" air dryers really get your hands any cleaner than old-school paper towels? Maybe not…

British researchers compared the effectiveness of different kinds of warm air hand dryers -- traditional, evaporative machines that require rubbing one's hands versus one that stripped moisture by way of high velocity air jets -- on 14 patients whose hands were contaminated with fresh, uncooked chicken, then washed multiple times with nonmedicated liquid soap and running water.

With warm air dryers, the difference in cleanliness depended on the necessity of rubbing one's hands together. Using traditional machines that required rubbing to get hands dry reversed the reduction of bacteria after handwashing. Why? The rubbing action during drying forces bacteria living inside the skin to emerge to the outside skin, then be transferred to other surfaces. What's more, the reduction of bacteria was the same among all warm air dryers when the hands of patients weren't rubbed together.

Among warm air dryers, the machine that stripped the moisture from hands performed better than the others. However, the old school approach of drying hands with paper towels lowered bacteria counts more effectively than any of the warm air dryers tested.

On the subject of washing, just a reminder to sanitize your reusable grocery bags often, especially after using them to transport raw meats from the grocery store to your home.

Journal of Applied Microbiology September 7, 2010 Free Full Text Study

ScienceDaily September 7, 2010