New independent research confirms jet hand dryers are safe and hygienic

Good hand hygiene has been in the spotlight since the beginning of the pandemic. Dyson has therefore commissioned test laboratory Airmid Healthgroup to investigate the aerosolisation of different drying methods. This new, independent study confirms that the Dyson Airblade is a safe and hygienic hand dryer for any washroom.

The study took place under realistic conditions: participants dried their hands after rising or washing them. The focus was on the effect of drying methods on the concentration of aerosols and bacteria in the air: a much discussed topic since the outbreak of the corona crisis.

Research method

Half of the participants rinsed their hands with water (without soap), the other half washed their hands for twenty seconds (with soap) according to World Health Organization (WHO) guidelines. The subjects then dried their hands with a Dyson jet air dryer or paper. The results show that small droplets mainly spread through normal activities in the toilet room, such as walking around or using a tap. Drying with a Dyson Airblade hand dryer makes no significant difference.

The study also shows that the increase in the number of aerosols and bacteria after drying with paper towels or with a Dyson jet hand dryer is similar. This proves that jet hand dryers are just as safe and hygienic as paper towels.

Previous hygiene studies

Immediately after the introduction of the first Dyson Airblade in 2008, several unrealistic studies were published on jet hand dryers. By examining the operation of hand dryers in extreme, unrepresentative conditions, several attempts were made to discredit jet hand dryers. In these studies, researchers applied abnormally large amounts of microbes (ETS in 2008 [1] and VSR in 2012 [2]) or even on plastic gloves (Wilcox in 2014 [3] and Redway in 2015 [4]), after which the hands were placed in the jet dryer without washing or even rinsing them. In reality, no one dries extremely dirty hands without at least having rinsed them off.

Several representative studies, with hands that were not artificially contaminated (SCA in 2013 [5]) or in real washrooms (Wilcox in 2018 [6]), already showed that there is no significant difference in aerosolization between the drying methods. A Dyson Airblade hand dryer turned out to be as hygienic as paper. This new study (Airmid in 2020) also confirms that Dyson Airblade hand dryers are a safe and hygienic solution for washrooms and is therefore in line with these previous representative studies on hygienic hand drying.

The World Health Organization (WHO) and the Centers for Disease Control and Prevention (CDC) also conclude that hand dryers are as hygienic as paper towels and prescribe both drying methods as the best way to dry hands.


[1] Redway K, Fawdar S (2008). A comparative study of three different hand drying methods: paper towel, warm air dryer, jet air dryer
[2] Terpstra P, Beumer R, Duisterwinkel (2012). Hygiëne handendrogers: Verspreiding van micro-organismen in de omgevingslucht door handen drogen met twee typen handendrogers.
[3] Best E, Parnell P, Wilcox M (2014). Microbiological comparison of hand-drying methods: the potential for contamination of the environment, user, and bystander
[4] Kimmit P, Redway K (2015). Evaluation of the potential for virus dispersal during hand drying: a comparison of three methods
[5] Margas E, Maquire E, Berland C, Welander F, Holah (2013). Assessment of the environmental microbiological cross contamination following hand drying with paper hand towels or an air blade dryer
[6] Best E, Parnell P, Couturier J, Barbut F, Le Brozec A, Arnoldo L, Madia A, Brusaferro S, Wilcox M (2018). Environmental contamination by bacteria in hospital washrooms according to hand-drying method: a multi-centre study


Whitepaper Hygiene in focus - Touch-free access in a clean building

Hygiene in Focus: What touch-free access in a "clean" building might look like in the future

Research shows that hygiene awareness has increased considerably in 2020. For example, two out of three people want to wash hands immediately after touching door handles, handrails and other contact points. In 2019, that was only a third. In addition, 83 percent of respondents said they would touch as few objects as possible on a daily basis, such as door handles, a guide rail or push buttons. A year earlier, that was just over half of those surveyed, 53 percent.

People have become more disciplined when it comes to hygiene. For example, a Forsa survey conducted on International Hand Hygiene Day shows that 93 percent of people wash hands immediately when they get home. In 2019, that percentage was much lower – at just 71 percent.

Hygiene also plays a major role outdoors. Architects, planners and building managers are more concerned than ever with addressing questions such as: “How can the fear of contamination in buildings be reduced?” and “How can infection prevention and control be reduced?”

Reducing the number of hand contact points is a common answer. For example, using a touch-free access, of which touch-free doors are an essential part. Dormabaka indicates that the optimal building hygiene strategy consists of a combination of four components:

  • automatic door systems
  • touch-free door openers
  • touch-free access control and
  • other measures and technologies.

Since each building has separate requirements, it is necessary to look at the way how these components are assembled. A hospital has different hygiene standards than an office environment. A laboratory where microbiological substances are used is subject to stricter guidelines than in the already strictly regulated food production. And in the hospitality industry, such large flows of people never take place as at an airport. An experienced solution provider can advise you on the choice of suitable (combination of) technologies.

 

Hygiene strategy for buildings

 

The full white paper can be downloaded here (in Dutch):


Chirec Delta Brussels - hand drying - Touchfree Toilet

Research from the paper industry shows that jet dryers are just as hygienic as paper towels

Chirec Delta Brussels - hand drying - Touchfree Toilet

The latest figures show that paper towel producers lost more than $800 million in revenue between 2012 and 2020 due to competition from electric hand dryers. Since the introduction of electric jet hand dryers, the paper industry has conducted several studies to show that jet hand dryers could be less hygienish than paper towels.

The European Tissue Symposium (ETS) is a Brussels-based organisation that represents the interests of the paper tissue industry, including Kimberly-Clark and SCA. Their task is, among other things, to limit the revenue lost, by going on the attack against jet dryers and spreading misleading information. Since 2008, for example, the ETS funded and published a research in an attempt to discredit jet hand dryers to the general public.

In 2017, a detailed plan was published on the ETS website that revealed how – with the help of a publicity campaign – electric hand dryers would be attacked. However, that campaign was based on misleading scientific research. The study, which focused on the spread of antibiotic-resistant microbes, was commissioned by the University of Leeds in the toilets of three hospitals in France, Italy and the United Kingdom. The results of this study show that there is no clear conclusion to be drawn about the difference in hygiene between use of paper towels and jet dryers. Nevertheless, in the media a story is spread that paper is more hygienic and misleading information about the hygiene of hand dryers is disseminated.

Earlier, in 2015, the ETS paid a researcher from the University of Westminster. During his experiment, the researcher artificially infected gloves with an abnormal amount of microbes, about 100,000 times more than normal. Then the hands were placed – without washing them – in the dryer to let the viruses be blown away. Based on that unreasonable experiment, the researcher concluded that paper towels are more hygienic. Subsequently, the ETS paid the Brussels public relations firm Duo Media more than € 100,000 to disseminate these misleading conclusions without mentioning the (unrealistic) method used.

This all followed an earlier study of the paper industry in 2013, which was done by SCA Hygiene Products (the parent company of Tork) and Campden BRI. This study concluded that, under normal circumstances, the use of a jet hand dryer does not have a significant impact on the amount of bacteria in the air of a toilet space compared to paper towels.

A detailed analysis of these three studies of the paper industry can be found here:


Woman washing her hands at the sink.

Washing and drying hands properly in fight against coronavirus

Woman washing her hands at the sink.

Since the coronavirus surfaced in early January, governments around the world have been in a battle of preparedness. The number of infections is also increased in our regions. However, scientifically based directions to this are often overshadowed by disinformation. What information is correct and above all: what can we do ourselves? The simplest advice turns out best: wash your hands more often and in a correct way. The effective drying of the hands, with a paper towel or a qualitative hand dryer, is an often forgotten but not to be underestimated step.

How is the coronavirus spread?

Research by the Chinese Center for Disease Control and Prevention (CCDC) shows that the coronavirus (covid-19) spreads through ‘drip dispersal’ – in other words, the virus only passes from human to human through the tiny droplets released during coughing and sneezing. According to recent studies, it travels on coughed-up droplets larger than 5 to 10 microns (one thousandth of a millimeter), which quickly fall down again, and thus end up on the surfaces that surround us.

The Dutch National Institute for Public Health and the Environment (RIVM) states that one assumes a distance of up to two meters: the virus does not ‘fly’ any further than that. Moreover, there is no clear evidence that the virus can stay in the air for a longer period of time and spread in this way. This means that the coronavirus is not proven to spread through air, air blowers or air conditioning systems. The World Health Organization (WHO) also confirms that only those who inhale droplets or enter through the hands in the mouth can become infected.

How can we prevent the spread of the coronavirus?

At this time, there is no vaccine for the coronavirus available. Prevention in this is better than cure. Medical professionals and governments rightly stress that hygiene is the key word in the fight against covid-19, and one refers specifically to the importance of good hand hygiene. Washing hands regularly and thoroughly with soap and water is proving to be one of the most efficient ways to protect yourself and others. If this is not done in the correct way, then this action misses its effect. Even the efficacy of disinfectant hand gel decreases if you do not wash your hands properly first, says Professor Marcel Zwietering (Professor of Food Microbiology at Wageningen University & Research).

However, what is not sufficiently mentioned in the news coverage is that drying your hands properly is at least as important. However, drying the hands is accompanied by a lot of risks of re-contamination. Wet or moist hands are breeding grounds for bacteria and spread up to a thousand times more bacteria on the surfaces they touch. The two leading international health organizations, the World Health Organization (WHO) and the Centers for Disease Control and Prevention (CDC), therefore prescribe to dry hands with a paper towel or an air hand dryer.

Are electric jet dryers safe with regards to coronavirus?

During a toilet visit, several contaminated surfaces are often touched, both before and after hand washing: opening the toilet door, opening and closing the tap and touching the towel roll, paper towels or button of a hand dryer. All these surfaces can be contaminated with bacteria by contact.

Since the coronavirus in particular is spread by touch and most jet hand dryers are operated completely hands-free, you avoid unnecessary – and therefore risky – touches. When using paper towels, you are more likely to pass on the coronavirus through touch. Also a regular towel or a cotton-roll system are not good alternatives, since that way you can also get bacteria or viruses from other users.

Some jet hand dryers are equipped with a HEPA filter and ensure that almost all bacteria are filtered out of the air before they blow your hands dry. Up to 99.95% of the particles are removed from the air before it lands on your hands. Partly for this reason, such jet hand dryers are used in modern hospitals. Similarly, in the disinfection areas of the special hospitals built in China to treat coronary patients hand dryers with HEPA filter have been installed, such as in the Shenyang Infectious Disease Hospital.

HACCP International, a leading food technology organisation, has certified a number of electric hand dryers as hygienic. The HACCP certificate guarantees that the appliance meets the highest requirements regarding the process of hand hygiene. Because, among other things, contamination is a constant threat in areas where food is produced, such hand dryers are ideally suited for this.

However, there are reports that hand dryers are blowing around bacteria and viruses, but these are unfounded. The researchers behind these studies – which were funded by the paper industry – did not use a methodology that reliably simulates its use in a realistic setting. There is therefore no scientific basis to support the claim that jet hand dryers with HEPA filter are unhygienic or spread bacteria and viruses.

There is no doubt that hygiene is number one in the fight against coronavirus. Washing hands and – remember – drying them thoroughly afterwards, with a paper towel or a good hand dryer, is the recommendation when it comes to preventing further contamination.