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Julianna Metzler
CHM 131-160
Fall 2014
Hand Dryers: Saving the Environment, but Not Our Health
It has been said that not only are electric hand dryers more energy efficient and eco-
friendly, but they also help to stop the spread of germs. However, that statement may not be true.
Hand dryers can actually increase the amount of bacteria on hands, and can spread cross
contamination in public washrooms. According to Keith Redway, a Senior Academic in the
Department of Biomedical Sciences at the University of Westminster, “From a hygiene
standpoint, paper towels are clearly superior to electric hand dryers” (Redway).
There have been many studies done on the effectiveness of removing bacteria from one’s
hands when drying them, but the most prominent ones include: The University of Westminster’s
“Study Finds Paper Towels More Hygienic”, Queensland University of Technology’s “Paper
towels may be more hygienic than air dryers” study, and The Myth Buster’s TV show episode,
“Down and Dirty”. The theory was that hand dryers not only save the trees that would be used to
make paper towels, but also would remove more bacteria than paper towels. The University of
Westminster was the first to publish any studies about the effects of electric hand dryers versus
paper towels in regards to bacterial removal and prevention of cross contamination (Redway).
Their study “measured the number of bacteria on subjects’ hands before washing and after
drying them using three different methods — paper towels, a traditional warm air dyer and a new
high-speed jet air dryer” (Redway). The experimenters swabbed the hands of the test subjects
before washing and after drying to measure the number of bacteria on subjects’ hands (Redway).
The Queensland University of Technology performed a similar experiment to the University of
Westminster’s. Their experiment also tested the effects of paper towels, air dryers, and jet air
dryers on the amount of bacteria found on the hands by swabbing test subjects’ hands before
washing, after washing, and after drying. (NHS Choices). Lastly, Myth Busters enlisted 16
volunteers to “have their hands sprayed with a harmless strain of Escherichia coli bacteria, then
swabbed for a sample, then washed using water but no soap, then swabbed again, then dried
using paper towels, then swabbed a third time. Then they repeated the process with the same
volunteers, bacteria and washing technique, but using hand dryers instead” (Savage). The
processes for all three major experiments are fairly similar, and not surprisingly, so are the
results.
Each experiment performed found that paper towels are much more effective at removing
bacteria from the hands than either of the electric hand dryers. The University of Westminster
found that “paper towel drying reduced the average number of bacteria on the finger pads by up
to 76 percent and on the palms by up to 77 percent” (Redway). Not only that, but the University
of Westminster found that the “electric hand dryers actually caused bacteria counts to increase”

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(Redway). Myth Busters found evidence with very similar numbers as well. In their study, “the
paper towels removed 71 percent of the bacteria on the volunteers' hands, while the hand dryers
only removed 23 percent” (Savage). Queensland University agrees, and supports this evidence
by saying “that using a paper towel was the best method of removing bacteria, especially from
the fingertips” (NHS Choices). Not only are electric hand dryers less effective in removing
bacteria from hands, but they also spread the germs on the subjects’ hands further across the
bathroom, causing cross contamination. The University of Westminster tested the amount of
cross contamination that air dryers can cause and measured that “The jet air dryer was capable of
blowing micro-organisms from the hands and the unit and potentially contaminating other
washroom users and the washroom environment up to 2 meters away, and the use of a traditional
warm air hand dryer spread micro-organisms up to 0.25 meters from the dryer, while paper
towels showed no significant spread of micro-organisms” (Redway). Queensland University
found similar numbers when they studied the amount of cross contamination caused by each
drying method. “Electric dryers spread the bacteria up to three feet (about a metre) from the unit,
while no dispersal was found when using paper towels” (NHS Choices). Myth Busters also
tested this, and swabbed the areas where each drying method occurred to find a bacteria count.
They found “3 [bacteria] for the paper towels and 41 for the hand dryers” (Savage). This is a
very important find, and suggests that “the use of warm air dryers and jet air dryers should be
carefully considered in locations where hygiene is of paramount importance, such as hospitals,
clinics, schools, nurseries, care homes, kitchens and other food preparation areas” (Redway).
References
NHS Choices (Ed.). (2013, June 6). Paper towels may be more hygienic than air dryers.
Retrieved November 1, 2014, from http://www.nhs.uk/news/2013/06June/Pages/Paper-
towels-may-be-more-hygienic-than-hand-dryers.aspx
Redway, K. (2008, November 15). Study Finds Paper Towels More Hygienic. Retrieved
November 1, 2014, from http://www.crosscountryinstall.com/pdf/Study Finds Paper
Towels More Hygienic.pdf
Savage, A., & Hyneman, J. (2013, May 15). Down and Dirty Results. Retrieved November 1,
2014, from http://mythbustersresults.com/