In April 2021, Japan followed other governments around the world (including UK) and revised its COVID-19 regulations advising commercial facilities and businesses to start using them again. It had imposed a ban during the pandemic due to insufficient data to rule them out. Now that this data has been collated and analysed by the Hygiene and Microbiology Research Centre in Tokyo it has declared that “hand dryers do not spread infections”.
This follows similar findings by WHO and CDC approving their use during a pandemic.
There is no sufficient evidence that shows hand dryers allow for greater risk of contracting the virus
There is no significant difference in the hygiene between paper towel use and hand dryers. (Based on in-depth, independent studies not conducted or funded by the paper towel or hand dryer industries over the last 30 years)
If you wash your hands properly then any hand drying method can be used without any significant risk of spreading COVID or any other infection.
Provide hand drying facilities – paper towels, continuous roller towels or electrical dryers
But which is better; hand dryers or hand towels?
Firstly, a distinction must be drawn between conventional Warm Air Hand Dryers and Jet or Blade Hand Dryers. A study in New Zealand (funded by New Zealand Towel Service) came down on the side of paper towels, although it did compare towels to Warm Air Dryers which can take up to 40 seconds to dry your hands by evaporation, which no one wants to wait around for. Many other reports published where hand dryers have come out worse are funded by paper towel manufacturers or the European Tissue Symposium.
European Tissue Symposium Washrooms with jet air dryers may have higher levels of environmental microbial contamination than those using single-use paper hand towels
It would be easy to draw the conclusion that they may have a bias towards paper towels. While the integrity of the testing house itself should not be called into doubt, it has been said that many only publish data that supports their own viewpoint. For example, a report in the Journal of Applied Microbiology stated
“Air impaction sampling showed no significant evidence of any difference between the methods of hand drying with respect to airborne microbial counts”
This report was commissioned by a paper towel manufacturer but, crucially, was never promoted. On the flip side, many studies which speak positively of hand dryer hygiene are carried out or funded by hand dryer companies.
Using a Dyson hand dryer releases no more bacteria into the air than removing your coat. Tests carried out independently by University of Bradford published in the Applied Journal of Microbiology have proved that Airblade technology is as hygienic as paper towels.
It is important to say that the funding body or company does not force or dictate the outcome of the study, these are usually carried out by independent bodies and in some cases, peer reviewed.
Leading independent microbiologist, Dr. David L Webber, has confirmed that the use of hand dryers in the washroom does not contribute to the spread of ..COVID-19
The best protection against contamination is proper hand-washing and proper hand-drying. Not drying your hands properly is a source of transmission of bacteria from and to your hands. A report by the Department of Medicine at the University of Auckland have shown that wet/damp hands spread as much as 1000 times more bacteria than dry hands.
Wet hands spread germs more easily than dry hands do. So it's important to thoroughly dry your hands after washing.
So, no matter what method of drying your hands is employed, it is imperative that they are properly dried (this rules out all slow, inefficient and ineffective hand dryers as ultimately users will leave with wet hands or wipe them on their clothes – which is definitely not hygienic).
The method of testing is also important. Some reports have tested both paper towels and hand dryers by coating the hands in bacteria and then drying them without washing them. This is fundamentally flawed. People who do not wash their hands usually do not dry them. Testing the level of transmission of bacteria from hands that aren’t washed is always going to show a spread. People should wash their hands and dry them properly to prevent onwards contamination. (Hjelt Institute of Hygiene and Microbiology of the University of Helsinki) Journal of Applied Microbiology – Using a Dyson Airblade reduces the amount of bacteria transferred by the skin by up to 40% Study by the College of Medicine at the University of Florida showed that 1 in 5 hand towel dispensers were found to be empty. This is something we have all experienced. Although I’m sure we have all come across a faulty hand dryer in our time.
What type of hand dryers might be considered 'hygienic' ?
A hygienic hand dryer must have some inherent feature which improves the hygiene of the dryer or the air quality passing through the dryer or beyond. A hand dryer can be classified as Hygienic if it has either HEPA filters (at least HEPA-13 Grade) or a built-in air steriliser unit, or both. Many dryers have anti-microbial covers. While it is better for the surface to be treated to prevent bacterial growth, the surface of the hand dryer does not form a particular function in the hand-drying procedure. As such, this would not classify it as a ‘hygienic hand dryer’.
HEPA Filtered Hand Dryers
Many hand dryers have a filter, although the standard of these vary greatly. Any form of mesh or foam may be called a filter.
The best type of filter is a HEPA filter, in particular a HEPA-13 filter. This is the grade of HEPA filter which is used by hospitals in air changing and in aircraft. A HEPA Grade-13 Filter will remove 99.95% of airborne contaminants as small as 0.3 microns. With relation to the COVID-19 pandemic, the coronavirus itself is between 0.075-0.160 microns which is too small to be captured by a HEPA filter on its own.
Aerosol particles, however, are the main transmission method of the virus as the virus is contained in moisture particles, from someone coughing, sneezing, shouting etc. These are approximately 5-10 microns so well above the size to be captured by a HEPA filter.
So, no matter what method of drying your hands is employed, it is imperative that they are properly dried (this rules out all slow, inefficient and ineffective hand dryers as ultimately users will leave with wet hands or wipe them on their clothes – which is definitely not hygienic).
The method of testing is also important. Some reports have tested both paper towels and hand dryers by coating the hands in bacteria and then drying them without washing them. This is fundamentally flawed. People who do not wash their hands usually do not dry them. Testing the level of transmission of bacteria from hands that aren’t washed is always going to show a spread. People should wash their hands and dry them properly to prevent onwards contamination. (Hjelt Institute of Hygiene and Microbiology of the University of Helsinki) Journal of Applied Microbiology – Using a Dyson Airblade reduces the amount of bacteria transferred by the skin by up to 40% Study by the College of Medicine at the University of Florida showed that 1 in 5 hand towel dispensers were found to be empty. This is something we have all experienced. Although I’m sure we have all come across a faulty hand dryer in our time.
Care when replacing HEPA filters.
A virus can live on a hard surface for up to 72 hours. The life of the virus within a filter has not been measured. When changing a filter, proper PPE should be worn including FFP2/3 mask, visor and gloves. The HEPA filters should be placed into a sealed container or bag, which can be disposed off in the normal waste stream as they are not classed as infectious unless they have come from an environment where they are considered certain to have come into contact with the virus – eg a COVID ward in a hospital or nursing home.
Aerosoled particles containing the coronavirus will become trapped within a HEPA filter and will not pass through. Given the half-life of the virus, it is expected that any live virus will be inactive within 24 hours.
Sterilising Hand Dryers
Air Steriliser technology has been around for many years in various forms (UVC direct irradiation, Corona discharge, ozone, ionisers etc), but the latest air sterilising technology uses a combination of techniques to provide an all round sterilisation process using Hydroxyl Radicals, SuperOxide Ions, Targeted Ozone, UVC irradiation. (See How OXIZONE Air Steriliser works).
Combining an air steriliser into a hand dryer makes such good sense. Not only is the inside of the dryer kept hygienically clean (it is pulling through air from the washroom after all), but the air it is blowing onto your hands has a sterilising effect. This charged, treated air doesn't stop its sterilising process at your hands, it continues throughout the washroom sterilising walls, floors, cubicles and doors as it goes. The best sterilising hand dryers have a run-on feature, so they do not stop this sterilising process once the hand dryer deactivates, they run non-stop, reducing bacterial growth in the washrooms and even removing odours.
NSF Protocol P335
Only 1 dryer has so far been awarded accreditation by the NSF under Protocol P335. Dyson Hand Dryers are certified as hygienic by the NSF based on their HEPA filter (which must filter out dust and bacteria) and they do not feature a reservoir to collect the water discarded from hands which will inevitably stagnate. To comply with P335, any stored water must be continually treated by some form of sterilisation. Other factors taken into consideration are drying time (less than 15 seconds), heat and automatic operation.
HACCP
Dyson hand dryers are approved for use in food industries by HACCP
General Washroom Hygiene
Studies carried out have shown that air conditioning and ventilation systems have contributed to the spread of airborne particles. Usually washroom ventilation is by extraction. No ventilation systems that introduce air into a room from another room should be used. A study in Wuhan during the COVID-19 outbreak detected the virus RNA in hospital staff changing areas and unventilated toilets, although this does not necessarily indicate the presence of an infectious virus. In a well-ventilated washroom (which most should be, but obviously not all) there should be no greater risk of contracting COVID than any other closed space. Most washrooms have a higher refresh rate than other rooms, typically 8-12 times per hour. In fact, if the washroom is fitted with an air steriliser (such as OXIZONE), there is a much lower and indeed negligible risk.
In a UK study, 99% of people visiting the bathroom said they washed their hands after going to the toilet. Recording devices installed in the bathrooms showed than only 32% of men and 64% of woman actually did. https://www.transplumb.com/news-archive/news-2017/16-03-17-srticle-proper-handwashing-and-drying
Global Washroom Hygiene Study
Changing behaviours in the washroom
Since the Coronavirus pandemic started, almost two thirds (63%) of people in the UK are less likely to leave a washroom without washing their hands In a recent global hygiene study, Dyson looked at how attitudes towards the washroom and general hand hygiene have changed since COVID-19 started.
Results from the Dyson global study show that whilst people are more conscious of the importance of hand hygiene since the pandemic started, more than one in ten (11%) people globally admit that they are more likely to leave the washroom without washing their hands, and 42% of people feel a lot more concerned visting a public washroom compared to this time last year. In UK specifically, this figure increases as almost half (47%) appear to be even more concerned visiting a washroom now compared to the same time last year. Over in the US, a fifth (20%) of male and younger people (19-29 years) are more likely to leave a public washroom without washing their hands.
Hands up for hygiene
The study also found that while respondents were concerned with hand hygiene, some still disregard the importance of hand washing and drying: leading health organisations stipulate you must wash your hands frequently with water and soap for at least 20 seconds – as well as dry your hands properly. The study revealed that since the outbreak only 40% of people stated hygiene considerations as their main purpose for washing their hands, for some it was just a habit (14%) and a small number like the feel of clean hands (11%). However, it also found that if the washroom has no working hand dryers or paper towels, some respondents were likely to let them dry naturally (25%) or dry them on their trousers or top (15%).
