James Dyson's Airblade
I've never been a fan of hot air hand dryers. One reason is because I never feel they quite dry my hands and another is they overheat any rings I may be wearing at the time. On a hot day the last thing you want is hot air to dry your hands after you've used soap and hot water for washing. My solution, if there are no paper towels available, is to use tissues to dry my hands.
In the past year there has been a heated argument between Dyson, the maker of the Airblade dryer and Kimberley Clark, the US paper towel corporation. Last March, Kimberley Clark published research which claimed there are 'significant hygiene risks associated with jet air dryers and warm air dryers'. The tissue paper trade organisation which prepared the report also claimed that jet air dryers increase bacteria on the hands by up to 42%. Dyson retaliated by producing hygienic credentials including the Royal Society of Public Health and claiming his dryer was the only one to have the Carbon Trust's Carbon Reduction Label.
None of this impresses me.
Dr Karl states hand drying should not just remove water, it should also remove bacteria. Researchers had a real surprise when they counted the bacteria left on the fingertips after paper towels, continuous-loop cotton towels and warm air dryers. Those who used the first two methods of hand drying reduced their bacterial count by about 45-60%, but washing and then using a warm air dryer increased the bacterial count by an average of 255%.
He asks: How could drying your hands increase the number of bacteria on your skin? The answer seems to be inside the warm air dryers, thanks to the moist environment. Every single warm air dryer they tested had high bacterial counts on the air inlet, while 97% had them on the outlet nozzle surfaces as well. These were the figures for warm air blowers in public toilets and of course, if you choose to do your measurements in a clean laboratory, you'll find lower bacterial counts.
According to Dr Karl, you can dry 90% of the surface area of our hand within 10 seconds with a towel. If the towel is on one place in a washroom and the bin in another, you can dry 90% of your hands while you walk from one place to the next. A warm air dryer can't dry your hands within 10 seconds. On average it takes 50 seconds to dry 90% of your hands.
With the new jet air dryers (such as Dyson's) you can rub your hands together and dry 90% of your hands within 10 seconds. Dr Karl's advice is to get into the habit of regularly washing your hands with soap and hot water and drying them. Using your jeans or even your hair is better than not drying them at all.
"And don't believe that warm air dryers were installed to improve hygiene. They are purely a cost-cutting measure. Anything else they tell you is a lot of hot air." Indeed.