This article was taken from the May 2013 issue of Wired magazine. Be the first to read Wired's articles in print before they're posted online, and get your hands on loads of additional content by <span class="s1">subscribing online.
In his recent paper, The Hygienic Efficacy of Different Hand-Drying Methods: A Review of the Evidence, published by Mayo Clinic Proceedings, biomedical scientist Cunrui Huang from Queensland University of Technology took a close look at hand drying. A trip to the toilet will never be the same...
Hot-air dryers
A standard hand-dryer takes 30 seconds longer than a towel.
This time difference is important: wet hands support and transmit more bacteria. "But rubbing hands while under hot-air dryers leads to greater bacterial numbers and airborne dissemination," Huang warns. "It might be that rubbing hands causes bacteria to migrate from hair follicles to the skin surface."
Jet-air dryers
Jet-style dryers are fast: ten seconds of being blasted with one is more effective than 30 seconds under a conventional dryer. But they lead to greater contamination of the toilet, as they can disperse bacteria further. And they're noisy: "In washrooms with jet air dryers, the noise level could constitute a potential risk to those exposed to it for long periods," says Huang.
Paper towels
The clear winners when it comes to hygienic hand-drying, paper towels attain a dryness of 99 per cent after 15 seconds' drying time, or 90 per cent after ten seconds, according to two of the studies reviewed. Paper towels are also easy to recycle. "Hand hygiene adherence would possibly decrease if paper towels are not available in washrooms." summarisies Huang.
This article was originally published by WIRED UK
