24th November 2014
A few days after this research was published and accompanied by the kind of journalistic headline the sponsors hoped for, enquiries into our cold plasma hand drying technology have gone through the roof. The University of Leeds produced the research, presumably unaware that a discovery made by its own scientists some 40 years ago has been used in a new hand drying technology which is producing quite contradictory evidence. The hydroxl radical and its effect on breaking down the structure of bacteria was their discovery and now eXtremeAir CPC hand dryers have a cold plasma generator inside which splits the structure of moisture to create hydroxl radicals in and around the hand dryer and hands as they dry. To find out more about CPC technology hand dryers click on the link.
Back to the research on conventional warm air hand dryers and the Dyson Airblade.
This comment we found posted by a healthcare professional on the NHS website says it all about practical usefulness of the recent 'microbiological comparison of hand drying methods...' produced by the University of Leeds and funded by the European Tissue symposium'
'Horrified that ETS funded this. Even more horrified that Leeds University commissioned & published this data. Absolutely astounded that the 'peers' accepted it. This is journalistic & grant-seeking nonsense research. I can finds 'bugs' anywhere (more or less) but whether they are viable, virulent, pathogenic, able to overcome the human barriers, present at worrying inoculum levels and so on is the question that needs to be answered. Epidemiological studies are the main tools for such research - not swabbing toilet seats & the like. Goodness, if we lived our lives on the basis of such research we would all live in a sterile bubble.
In fairness to the NHS website, unlike the journalistic nonsense appearing in the mainstream press it does impose limitations on the value of the study. The bullet points below are directly taken from the NHS site:
- One important limitation of the study is it may not replicate the real-life condition of someone having just thoroughly washed their hands with soap and water, and then drying their hands. In this experimental situation, the users had gloved hands contaminated with either lactobacilli or black paint and then dried their hands. In effect, this may be seen more to replicate the scenario of someone going to the toilet and then proceeding straight to the hand dryer without washing their hands first. A more suitable test may have been to coat the gloves with either bacteria or black paint, wash them with soap and water as recommended, and then proceed to the hand dryers to see how many bacteria or paint were spread.
- The spread of heavier black paint may also not be equivalent to the spread of viruses and bacteria, though it may represent the spread of water.
- Aside from the assessment of the surrounding environment and bystanders, another important area of consideration would also be to compare how much bacteria remained on the surface of the users' hands after drying with each of the three methods. This is of equal importance in knowing how much bacteria remains on the users' hands that could be transferred to other surfaces. It would be valuable to know whether there was any difference. This study has not specifically examined this aspect, though in fact it did note few paint spots remained on the hands after drying with either of the hand dryers.
- It also would have been valuable to consider comparing the amount of bacteria or paint left on the towel dispenser or hand dryers after use, and how much of this would usually be transferred to the next person's hands during hand drying.
It is universally acknowledged that it is the cleanliness of the hands that is important as this is a transmission point, so it is this that needs scrutinising in most detail.
After all, paper towels do not kill residual bacteria, they may scrape some off but are then either deposited in a open or closed bin or often on the floor in many high traffic bathrooms, They are effectively a moist collection points for bacteria themselves but how big a deal is this really in either case? You are no more likely to touch the wall behind a hand dryer as you are handle a used paper towel, used paper towels have a much higher chance of transporting bacteria around a much greater distance and also creating an extra touch point on toilet bins.
We have some interesting independent research carried out by two of the USA's leading microbiology labs, EMSL Labs is an elite CDC-certified lab with AIHA accreditation in industrial hygiene and environmental microbiology and Antimicrobial Test Labs, ATL, a GLP-compliant laboratory audited by the EPA and FDA. This research applied more relevant bacteria (i.e. the sort that will actually harm us) such as MRSA, Staph, Salmonella and e-Coli onto vitro skin, which is universally acknowledged as closely representing human skin with its crevices for bacteria to hide. The cold plasma enhanced airflow was passed over the bacteria for 30 seconds and a quite significant kill rate recorded. Interestingly even without the cold plasma and just the warm air some of the bacteria was reduced.
So lets get all the research in front of a true set of independent professionals and then have a more balanced discussion about this. The press as ever are completely irresponsible and in danger of unnecessarily scaremongering and making people consider a very environmentally unfriendly way of doing things once again!
*** 2017 update – please note the above information regarding CPC technology was correct at the time and date the post was published. We are awaiting further guidance from the manufacturer regarding the efficacy of these claims.
If you have any questions about any of the comments in this article please feel free to contact us
For more information or for help in finding your ideal hand dryer, please contact us on 0114 3540047, use our contact us page by clicking here or click to visit the website. You can also use our Intelligent Search Tool that helps you identify the perfect dryer for your location by clicking here
In the trade? Don't forget we can set you up with a trade account for your purchases.
We have wholesaler, contractor, public sector and charity discounts available, please don't hesitate to ask or find out more information by clicking here.