On 2006-08-23, Jerry wrote:

How are hot air hand dryers unsanitary?

http://www.guardian.co.uk/consumer/s...730463,00.html

-- In the 1990s, the University of Westminster's School of
-- Biosciences - sponsored by the Association of Makers of Soft
-- Tissue Papers, it must be stressed - carried out some
-- studies into the difference in hygiene between paper towels
-- and dryers. The results are of interest, though, because
-- they show how long you must use a dryer to dry your hands,
-- something that the manufacturers rarely allow for in their
-- calculations. The studies concluded that warm-air dryers
-- were found to "significantly increase general bacterial
-- counts on the hands by an average of 255%", whereas towels
-- reduced general bacterial counts "by an average of 58%
-- (paper) and 45% (cotton)".

http://www.cleanseats.com/toilet_sea...article-7.html

-- Hot air driers, which were installed in public wash-rooms to
-- reduce the expense and litter of paper towels, are far less
-- "sanitary" than paper or cotton towels. A number of studies
-- of hot air hand driers, including Blackmore and Prisk (1984)
-- and Matthews and Newsom (1987), showed that hot air driers
-- were not effective in reducing the number of bacteria on the
-- hands. In fact, the rubbing of the hands under the hot air
-- device and the propelling of bacteria out of the hot air
-- jets combined to actually increase the number of bacteria in
-- the washroom. An additional complication, according to
-- Blackmore and Prisk, is that hot air driers take longer to
-- dry the hands than towels. Because only one person at a time
-- can use the drier, others may become impatient and wipe
-- their hands on their clothing or a handkerchief.
--
-- Another researcher, comparing bacterial residue on hands
-- after drying with the warm air device, paper towels or a
-- continuous cotton towel, found that the towels were
-- significantly better in removing micro-organisms. While the
-- electric devices increased bacteria on the hands by 162
-- percent, paper towels decreased bacteria levels by 29
-- percent.