Reading between the lines
Whether or not they’re actually better at drying your hands may be an open question, but according to research published in the Journal of Applied Microbiology, it may be (marginally) better at removing bacteria:
Conclusions: Effective hand drying is important for reducing transfer of commensals or remaining contaminants to surfaces. Rubbing hands during warm air drying can counteract the reduction in bacterial numbers accrued during handwashing.
Significance and Impact of the Study: The Airblade™ was superior to the warm air dryers for reducing bacterial transfer. Its short, 10 s drying time should encourage greater compliance with hand drying and thus help reduce the spread of infectious agents via hands.
I’m going to be honest – I’m no expert in hand-drying technology, but this report seems a bit… um… crappy. First, one of the authors is from Dyson’s microbiology group (they have a division of microbiology?!?) – the other two are from a university, but at first I had a bit of trouble with the possible conflicts of interest. Then I looked at the data. I feel like it exonerates them from any claims of shillery – If I were going to fake science for money, I feel like I could do a better job. I definitely believe the data, I just think their stated conclusions are a bit overblown.
Basically, they had people handle meat to contaminate their hands, then wash their hands, then dry their hands in one of several ways, and measured how much bacteria was on their hands. The results are laughable.
Using the Dyson drier was marginally better – it’s statistically significant (which means there’s a less than 5% probability that the difference observed is due to chance), but if the difference is between 300 and 200 CFU’s, I don’t think it’s actually functionally significant. Besides that, using a paper towel was actually quite a bit better than any of the hand driers.
Anyway, I don’t know why I spent an hour of my life reading and writing about hand driers and bacteria. But when an add says “[product x] has been scientifically proven to [wondrous action],” I’ve always wondered where that research comes from. Now I know.
Snelling, A., Saville, T., Stevens, D., & Beggs, C. (2010). ORIGINAL ARTICLE: Comparative evaluation of the hygienic efficacy of an ultra-rapid hand dryer vs conventional warm air hand dryers Journal of Applied Microbiology DOI: 10.1111/j.1365-2672.2010.04838.x