Wednesday, November 17, 2010

How to Dry Your Hands?

So I'm researching something for ASG (as I often find myself doing): what is the best way to dry your hands in the bath room? I just read a 35 page research paper (okay, power skimmed alot of it) that compared several types of traditional paper towels, warm-air hand driers, and the new Dyson hand-slot jet driers. The results were shocking!

My first instinct when someone from ASG suggested I look into this, was wow -- the Dyson hand driers (such as at Canton/Belden Village Mall) definitely have cool factor! I like'm. They actually shoot cool air in a jet to "scrape" the water off your hands. They advertise themselves as the fastest hand driers around, and the study pretty much confirmed that.

Bacteria grow on wet hands -- and in heat. So you want dry, not hot hands. And the study actually revealed that all paper towels pretty much dry your hands the same (~96%) after about 10 seconds. The Dyson Blade awesome thing also dries your hands to about 96% in 10 seconds. The hot-air hand driers actually take 3 times as long, are not at all efficient at drying your hands -- and in the process, actually promote bacterial growth! EW! Add to that, that the hot air actually shoots bacteria out of it if it's not properly maintained (which practically none are!) So hot air hand driers are officially the worst kind.

But the shocking part was that the cool-air jets (Dysons) while significantly better than the hot jets, also left some bacteria behind - and had the potential to shoot bacteria on to your hands, especially if you touched the device (which is likely if you look at the design.) Paper towels were significantly more efficient at drying your hands, and keeping you bacteria free. The study concludes with:

"The results of all parts of this study suggest that paper towels should be used in
locations where hygiene is paramount, such as hospitals, clinics, schools,
nurseries, care homes, kitchens and other food preparation areas. Warm air
dryers and jet air dryers should be carefully considered for these types of
location because of their poorer hygiene performance and the increased
likelihood of transmission of bacteria, including potentially pathogenic types, via
the fingerpads and palms of the hand and their air flows. The performance of
both the warm air dryer and the jet air dryer was inferior to paper towels in all
respects (drying efficiency, bacterial numbers on the hands, bacterial
contamination of the air flow and surfaces of the devices, and transmission of
bacteria in the washroom) with the one exception that the jet air dryer is equal in
drying efficiency. The jet air dryer was shown to be superior to the warm air dryer
in all respects except for similar bacterial contamination and greater transmission
potential. Although representing a considerable improvement over warm air
dryers in speed, the jet air dryer’s overall performance, with the exception of
drying efficiency, was significantly poorer than that of paper towels in all other
respects tested in this study."

Very interesting. But when it comes to having to chose between eliminating paper usage and being environmentally green, and which gets the most bacteria off of your hands and is the most healthy -- I'm going to have to go with healthiest option here, and recommend buying only recycled paper towels (since Clearly it doesn't seem to matter what paper towels you buy!) I'll look into more studies, but for now - I've made up my mind. My next step: How to make paper towels more environmentally friendly...


ASKON said...

Hand dryers is a best option for hand drying purpose.
Nice writing efforts, keep writing.
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Search2 said...

Very informative post, i am waiting for future post.
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