Drying your hands effectively is almost as important as washing them, but we often get asked how hygienic hand dryers are, really? This blog post asks the experts at Dyson to explain why hand dryers that contain a HEPA filter are a hygienic choice for your bathroom.
Towards the end of last year I wrote a blog piece entitled Paper Towels or Hand Dryers: which are better, in which I looked at the pro’s and con’s of using paper or hand dryers to dry your hands after washing.
Drying your hands effectively is almost as important as washing them, as bacteria breeds faster on wet hands than on dry, but the question of which dries hands better is a complex one. There are numerous factors to consider: price, the environment and personal preference to name but a few.
One of the factors I looked at in my previous piece was the widespread belief that hand dryers are unhygienic. A 2012 hygienic efficacy study of different hand drying methods, led by researchers at Queensland University in Brisbane, Australia put the “which is more hygienic” question to the test.
The study revealed that “from a hygiene viewpoint, paper towels are superior to electronic air dryers” and “drying hands thoroughly with single-use, disposable paper towels is the preferred method of hand drying.”
However – and this is important to note – the study found that rather than warm air dryers “growing” bacteria as is often suggested, the reason that paper is more effective at removing contamination is that friction caused by the physical wiping of hands with a paper towel is actually the key component in removing contamination.
Going (or growing) viral?
Despite this research, the prevailing view still seems to be that hand dryers “grow” bacteria, as evidenced by a Facebook post by a Californian health worker which went viral in February 2018 after she claimed that she had “grown” fungus from air that had been expelled by a public bathroom hand dryer.
The post, which was shared over 500 000 times, contained a picture of her petri dish experiment and the caption: “This is the several strains of possible pathogenic fungi and bacteria that you’re swirling around your hands and you think you’re walking out with clean hands. #nomorehanddryers #outlaw #spreadthenews.“
Her original post is below:
In an article that followed in the European Cleaning Journal, a Dyson spokesperson said that they were “keen to engage” and were approaching her research with an open mind. However, they did say that they felt the post contained far too little information to support its conclusions.
According to the Dyson spokesperson: “If the Petri dish was simply placed inside the aperture of a hand dryer and left there for three minutes as the wording suggests, then what has effectively happened is a sampling of the washroom air and similar results would be expected if the plate was left out in the open anywhere else in the washroom for three minutes.” Ward later altered her Facebook page to say: “This post is simply for awareness, not to instil fear.“
Do hand dryers grow bacteria?
Rentokil Initial South Africa are the sole supplier of Dyson hand dryers in South Africa, so we took this opportunity to ask Dyson directly for a comment on the “unhygienic” claim.
Dyson responded as follows: “While washroom air can contain microbes, all Dyson Airblade hand dryers have HEPA filters that capture 99.97% of particles as small as 0.3 microns (the size of bacteria) from the washroom air before it is blown onto hands, so hands are dried with clean – not dirty – air.
University of Bradford (UK) research, peer-reviewed and published in the Journal of Applied Microbiology, found that using the Dyson Airblade hand dryer reduces bacteria on washed hands by up to 40%. (More information about these studies can be found on Dyson’s website. Alternately take a look at this YouTube video for some interesting facts on the hygiene of hand dryers).
The image of microbes grown in an agar plate may look shocking, but in fact it tells us very little as we don’t know where these microbes came from, how exactly they were collected, or what they are.
Dyson Airblade hand dryers are proven hygienic by university research and our own extensive in-house testing. They are also certified by hygiene experts NSF. We estimate that 120 million pairs of hands are dried by Dyson Airblade hand dryers every day, and since their launch in 2006 they have been trusted by hospitals, food manufacturers, and businesses worldwide”.
So there we have it; some science to refute the idea that hand dryers “grow” bacteria and that to use them is to cover your hands in bacteria. In addition to Dyson hand dryers, Initial also offers Luna Dry, our own HEPA filter hand dryer. You can read more about the benefits of Luna in our article ‘Prepare to be blown away! Our Luna dryer is here‘. The HEPA filter present in both Dyson and Luna air dryers makes sure that hands are dried with clean – not dirty – air.
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