Is there a hygiene issue with jet air dryers? Why should we all care?
Because 95% of adults don’t wash their hands long enough to remove bacteria and germs, they can remain on hands after washing. So where do those remaining bacteria and germs go when using a jet air dryer? They blow off in water droplets, and can travel as far as 6-1/2 feet. And those aerosolised bacteria can linger in the air for up to 15 minutes. In fact, jet air dryers can increase the germ count on fingers by up to 42%.
What does the science say about jet air dryers? The science is clear:
Research shows that inner surfaces of jet air dryers have up to 48 times more contamination than the average toilet seat. Among the findings from a University of Westminster study, the research found high-speed and warm-air dryers can harbour bacteria on surfaces and inside dryers. This could lead to cross contamination if users reach inside and touch the surface of the unit or when bacteria could be carried in the airstream and deposited on wet hands – these germs include fecal bacteria such as E. coli, as well as Staphylococcus. An article in the Mayo Clinic Proceedings journal analysed the hygienic efficacy of these hand-drying methods. Their recommendation? Paper towels are the best hand-drying option in locations where “hygiene is paramount,” such as hospitals and clinics. The same review article determined that air dryers cause cross contamination and deemed them unsuitable for these environments. “From a hygiene viewpoint, paper towels are superior to electric air dryers,” the study concluded.(1)
So your hands could be more contaminated after using a jet air dryer than before you washed them?
Yes, the science shows that using a jet air dryer can increase the bacteria count on users’ fingers by up to 42% as compared to not washing them at all.
Don’t filters inside the jet air dryers make the surrounding air clean?
The filter ensures that the air blowing on hands is clean; however, with nearly 95% of adults
not washing long enough to thoroughly clean the bacteria and germs from their hands, it cannot stop the water on hands from being aerosolised and blown back into the restroom. In fact, using a jet air dryer can disperse up to 1,300 times more germ particles than just drying with paper towels, and a 2013 Eurofins study found that 1 in 8 floors below jet air dryers had Staphylococcal counts > 10 million (per 100 cm2). Even more surprising, 70% of the germs spread by jet dryers landed at the height of a child’s face.
What are the biggest advantages of paper towels over jet air dryers?
Towels can scrape off germs that remain after washing:
Single-use towels reduce bacteria on hands, removing up to 77% of the bacteria that remains after washing.
Towels may increase hand hygiene compliance:
According to the Mayo Clinic Proceedings review paper, “…given the strong preference for using paper towels, hand hygiene adherence would possibly decrease if paper towels are not available in washrooms.”(1)
People prefer towels!
An observational study during ISSA/Interclean in Amsterdam in 2016 revealed that 90% of people showed a behavioural preference for paper towels over jet air dryers in the washroom. Faced with a choice of drying methods, 90% of men and 91% of women chose paper towels over jet air dryers. Similarly, in a study funded by Dyson, the use of paper towels consistently out-performed all the other drying techniques, especially with regard to bacteria left on the palms and fingertips.(2) Jet air dryers can harbour bacteria on their surfaces and in their airstreams, which could lead to cross contamination. The bacteria could be carried in the airstream and deposited on wet hands.
What other publications and organizations have concluded that paper towels should be used over jet air dryers?
An article published in the Mayo Clinic Proceedings analysed the hygienic efficacy of different hand-drying methods. The article concluded that paper towels are the best hand-drying option in locations where “hygiene is paramount,” such as hospitals and clinics. It also determined that air dryers cause cross contamination and deemed them unsuitable for these environments. “From a hygiene viewpoint, paper towels are superior to electric air dryers,” the article specified. (1)
In addition, the World Health Organisation (WHO) “Guidelines on Hand Hygiene in Health Care,” recommends that workers “dry hands thoroughly using single-use towels.” (3)
Why is hygiene so important, particularly in the food industry?
The CDC estimates that 48 million people in the U.S. suffer a foodborne illness annually (1 in 6 people). These microbes are more easily spread when food industry workers don’t use proper hand washing methods and then return to work with bacteria and germs on their hands. The CDC also estimates that foodborne illnesses cause more than 127,000 hospitalisations and 3,000 deaths in the U.S. each year. Effective hand washing and proper drying remains our best defence. Jet air dryers harbour bacteria on their surfaces and in their airstreams – bacterial counts on the surfaces of jet air dryers can be up to 1,000 times higher than on a towel dispensers and staphylococci up to 800 times higher. And bacteria on unit surfaces could lead to cross contamination if users touch the surface of the unit or if bacteria are aerosolised in water droplets that could deposit on hands during use.
References:
(1) Huang C, Ma W, Stack S, “The Hygienic Efficacy of Different Hand-Drying Methods: A Review of the Evidence,” Mayo Clin Proc, 2012; 87(8): 791-798.
(2) Snelling AM, Saville T, Stevens D, Beggs CB, “Comparative evaluation of the hygienic efficacy of an ultra-rapid hand dryer vs conventional warm air hand dryers,” Journal of Applied Microbiology, 2010; 110: 19-26.
(3) WHO Guidelines on Hand Hygiene in Health Care. Published by the World Health Organization, 2009.
