Its been a long-standing battle between paper hand towel manufacturers and hand dryer companies to place themselves as the ultimate hand drying solution. What you believe depends on what you read, where you read it, who wrote it and what you want to believe!
To give an overview, we have looked at some reports and their credibility.
In 2005 a German Paper & Pulp Association-funded study showed that there was a 24% decrease in skin bacteria by using paper towel to dry your hands compared to a standard hand dryer which increased the bacteria by 117% (remember these were the days before high-speed-low-energy hand dryer and Dysons).
Dyson came out of the corner fighting in 2008 and became the first hand dryer to have the Royal Society of Public Health kite-mark for its 99.9% reduction in bacteria flowing in the air through its hand dryer by using hospital-grade HEPA-13 filters, claiming it as the most hygienic hand dryer and a “a significant step forward in hand-dryer technology”.
Deb – a paper towel and consumable manufacturer – also commissioned a study by Queensland University in Brisbane which showed that from a hygiene point of view, single-use paper towels were much superior to electronic hand dryers.
World Dryers (one of the world’s leading hand dryer manufacturers) reported that an unbiased, unsponsored report by the Mayo Clinic in 2000 reported that all hand drying methods are equally hygienic – including hand dryers.
In 2012 Campden BRI released a white paper titled “Personnel and Personal Hygiene” which reported “Warm air dryers have been shown to be as effective as paper towels with respect to the number of bacteria recovered from hands after washing and drying. In addition, there is no evidence to show that warm air dryers contaminate the air…”
Dyson also released a video showing the bacteria you could expect from using paper hand towels :
So how do we debunk or confirm these reports and the stories that surround them? It is true that most washroom hand dryers blow contaminated air onto your hands.
Before you think this is disgusting and unhygienic, which it may be, it is the same the air you are breathing in the washroom. It is the same air that is in contact with your clothes, your face and your hands. If you don’t want this contaminated air on your hands, you probably shouldn’t be breathing it either!
If you are still concerned about blowing contaminated air onto your hands, there are options.
The Dyson Airblade famously released its Smoke-Box Test. This experiment demonstrated the Dyson Airblade hand dryer being placed between 2 chambers with no access between the chambers apart from through the dryer itself. The bottom chamber was filled with smoke at the point where air is taken into the dryer and the top chamber is where the air comes out of the dryer – onto your hands. The results show what appears to be a 100% removal of the smoke showing how effective the HEPA filters are at removing contaminants (as small as 0.3 microns – that’s smaller than a virus!).
What about germs on the outside of the machine.
A lot of hand dryer manufacturers use an antibacterial coating on the outside of the machine. Nice idea, Im not sure how much this affects the user experience unless you are going to get all touchy feely with the sleek curves and contours across the hand dryer cover … each to their own though.
Sterilising Hand Dryers
Some hand dryers have a sterilising action on the air and in turn on your hands.
The AirSteril company developed the Sterillo hand dryer with the idea of not only purifying the air but maintaining an odour free washroom. The AirSteril Oxizone has long been used in washrooms to purify the air, removing odours and bacteria, not only in the air but on surfaces also. The technology uses a mix of techniques including plasma, and Titanium Oxide, small amounts of ozone. This technology actually disrupts the cell structure of viruses and bacteria and destroys them. Although we don’t at this point have any data on the efficacy of the sterilising action on your hands, these technologies are tried and tested in a number of industries, so it is perceivable that they do have a hygienic effect on your hands.
The American Dryer ExtremeAir CPC uses a different system – Cold Plasma. This is used widely in the USA to sterilise food in production before it reaches the supermarkets. Cold Plasma is considered to be the fourth state of matter. It is an electrified gas consisting of electrons, positive and negative ions, free radicals, gas atoms and molecules. Its non-thermal state make it ideal for deactivating pathogens on delicate raw and fresh foodstuffs. This same technology is used in the CPC to sterilised your hands under the hand dryer.
Other hand dryers use Ultraviolet sterilising. The problem with UV sterilising is that the wavelength of the light (UVC) used is harmful if you are to look directly at it. It therefore has to be housed inside the machine and can only sterilise the air that passes through its beams. This will have a sterilising effect on the air, how much so will depend on how long the air is exposed, the faster the air-speed in the dryer the lower the exposure time. Although we can’t say for sure how effective these are, there will be some decontamination of the air being used to dry your hands. Dryers that use UV Sterilising are Fumagalli UVC9000 and Aertek UV Blade.
Let’s get back to the bun-fight!
In 2016 there was wide spread media reports on Dyson hand dryers spreading “1300 times more germs than paper towels”.
The study, carried out at London’s University of Westminster and published in the Journal of Applied Microbiology, compared 3 hand drying methods : Warms Air Hand Dryer, Jet Hand Dryer and Paper Towels. The study was immediately lambasted by Dyson claiming it as misleading scaremongering by paper towel manufacturers. It is certainly true from what we can see that the study did not emulate a real-life situation. Rubber gloved ‘hands’ were coated in a virus (much higher than you ever find in a washroom) and placed straight into a Dyson Airblade hand dryer. There a couple of things that might strike you immediately. Firstly, who wears rubber gloves when they are going to the bathroom (you don’t need to tell us if you do, keep that to yourself) and secondly, surely people wash the hands before they put them into, or under, a hand dryer? – Surely fundamental!
Dyson didn’t take this lying down, rebuking the claims for the flawed methodology and uncovering a part of the report – unpublished – which including the hand washing step in which all the methods performed equally – paper towels, warm air dryer and Dyson Airblade. They also quoted the results from a ‘peer-reviewed study published in the Journal of Applied Microbiology that using the Dyson Airblade hand dryer reduced the amount of bacteria transferred from the skin by up to 40%. They also pointed out the because of the HEPA13 filters in the Dyson Airblade, it is one of the most hygienic hand dryers on the market and caused no more release of bacteria into the air than taking your coat off!
Their review of the various papers published – one of which was never promoted (a paper-towel company commissioned report) because it did not show any significant difference between the hand drying methods is well worth a watch. It obviously focuses on the Dyson Airblade but it shines a light into the murky world of claim and counter-claim, or as some might call it Fake News.
If you really want to avoid washroom bacteria, best you don’t go into the bathroom and if you must (lets face it, you must!), then proper washing of your hands and using a hygienic hand dryer (or paper towels, lets not be biased!) is the best protection. Leave the rubber gloves at home.