Hot-Air Dryers Suck In Nasty Bathroom Bacteria, Shoot Them At Your Hands (arstechnica.com)

An anonymous reader quotes a report from Ars Technica: Hot-air dryers suck in bacteria and hardy bacterial spores loitering in the bathroom -- perhaps launched into the air by whooshing toilet flushes -- and fire them directly at your freshly cleaned hands, according to a study published in the April issue of Applied and Environmental Microbiology. The authors of the study, led by researchers at the University of Connecticut, found that adding HEPA filters to the dryers can reduce germ-spewing four-fold. However, the data hints that places like infectious disease research facilities and healthcare settings may just want to ditch the dryers and turn to trusty towels. Indeed, in the wake of the blustery study -- which took place in research facility bathrooms around UConn -- "paper towel dispensers have recently been added to all 36 bathrooms in basic science research areas in the UConn School of Medicine surveyed in the current study," the authors note. The researchers speculated that "one reason hand dryers may disperse so many bacteria is the large amount of air that passes through hand dryers, 19,000 linear feet/min at the nozzle. The convection generated by high airflow below the hand dryer nozzles could also draw in room air."

Comments

Always suspected this.

[whoever57]

I think that the Dyson dryers are the worst. There is usually a small pool of water in the device, just ideal for bacteria to grow in, then the air blows, potentially taking tiny droplets of this bacteria-infected water into your face.

Re:Always suspected this.

[AxeTheMax]

You're paranoid. What about ATM's, hand rails, door bell buttons, hire cars? Everyday life in other words.

Rinsing is fine in most cases, except when your hands may have come in touch with faecal matter. Eating out is probably a greater hazard to you.

Re:Always suspected this.

[arth1]

That ethanol kills many germs isn't disputed, but it doesn't kill enough of them to really sanitize, and leaves the bacteria's food source, just smeared around.
It's like if you scrape off most of the mold on a piece of cheese, smearing it around a bit in the process. What do you think happens then?
The main difference is that bacteria multiply a heck of a lot faster than mold.

The best you can do for your hands are wash and rinse. And in public facilities, turn off the tap with a paper towel, not your hand, and open the door with your foot or elbow, not your still moist hand.

not really new news

[chromaexcursion]

Various studies have been published on this in the past few years.
The "sanitary" air driers are anything but. The more powerful they are the worse they are.
A little wasteful, but paper is better. If people wouldn't use far more than is necessary to dry their hands it would be less wasteful.
The small waste of paper is far less that one what's used to treat one person's infection.
Pay me now, or pay me later. Paper towels are less wasteful.

You're drying it wrong

[Anonymous Coward]

Once you know how to use them, they're brilliant and don't blow anything your face.

Take your wet hands, put them down the SIDES of the dryer (not the top!) and bring them into the dryer from the side. Draw them upwards slowly. That's it. The water sheets off the hands downwards and nothing goes upwards. Usually one draw is enough to make them bone dry, if you need to, repeat the in-at-the-side-draw-upwards action a second time.

DO NOT:
Stick your hands in the top, thrusting downwards, because the water will sheet up your arms and into the air.

Water doesn't fly up into your face, and the water going down is drained down.

Volatile

[DrYak]

If you pay attention to the article (yes, I know, /. , never RTFA), the mostly are interested in what is floating in the air.
As in spores that at some point of time got air born (TFS mentions "flushing" as something that might launch spores in the air)

The whole idea of the article, is that specifically exposing plates to the air flow of the air dryer gives much more bacteria colonies than anything else (sample the nozzle of a turned off air dryer, leaving the plate in an currently unused toilet room, blowing air with a less powerful small fan, etc.)
Their proposed explanation is that this contamination is due to the sheer amount of air that goes out of the dryer (there aren't that many microbes in the air, but when the whole atmosphere of the toilet room is cycled and blown to your plate in a few seconds, you're bound to catch a few microboes).

From that point of view :
  - Dysons have always been louded for their extremely powerful air flow and insanely efficient fan motors. That doesn't help the "blowing the whole room's worth of air to your hand" problem.
  - Dysons have a pool of water accumulating at the bottom, which will get blown at the exact moment when the dryer is used, helping the "getting microbe airborne" a tiny bit (would be as if someone did flush their toilet exactly in sync with a classical dryer, given TFS. Here the pool is smaller, but closer, but the effect should be tiny).
  - Touching the wall isn't a problem (sampling the nozzles of turned off dryer didn't produce much. Again, it's not that dryers are dirty. It's the fact that almost any particule currently in the air will end up being blown on your hands at some point of time in the cycle of these air blowing monsters. Unless dysons have HEPA filters, there's no reason to suspect they are any different from other dryers)
  - The direction where sheets of water flow isn't relevant to the perspective of this study.

Funnily though, even if TFS reports that paper towel were added to toilet rooms as a consquence of the study, at point during the study did they test the paper towel surface for microbes...

Tin foil hat ! Conspiracy theory time !! THEY WERE PAID BY THE "BIG SOFT TISSUE" !!!~~