Numerous studies demonstrate paper’s superior hand drying credentials – reducing hand contamination and cross contamination via air and surfaces
Hand hygiene is the cornerstone of infection control. Many illnesses are transmitted via the hands,i and so hospitals and clinical environments around the world enforce hand hygiene guidelines to minimise the spread of infection.
Hand hygiene is also promoted among the general public (not least during the COVID-19 pandemic). The WHO celebrates Global Hand Hygiene Day on 5 May each year, while Global Handwashing Day, founded by the Global Handwashing partnership, is endorsed by schools, governments and civil society across the globe on 15 October. These initiatives promote one, core message: ‘Clean hands are safer hands’.
Although the general population’s awareness of hand hygiene increased during the pandemic, most people do not understand the importance of optimal hand drying. Hand hygiene requires hand drying, as wet hands are more likely to transmit microbes to other touched surfaces. Now, scientists have sought to complete the picture by exploring the differences between hand drying options. Eminent virologists and bacteriologists at universities and hospitals in countries including France, Germany, Italy and UK, have performed studies to establish which is the most hygienic way to dry hands after washing:
Are some options better than others in reducing contamination?
Do some methods of hand drying have a greater propensity to disperse viruses – particularly on poorly washed hands? and
What are the implications of different hand drying options for the spread of pathogens in public washrooms, often visited by hundreds of people each day?
Their findings demonstrate the following:
Paper towels expose washroom users to fewer microorganisms.
A study by leading microbiology institute, Eurofins-Inlab,ii demonstrated how the hand drying method in washrooms has significant impact on the numbers of microorganisms including potential pathogens a user is exposed to and therefore the potential for microbial cross-contamination. Placing jet air dryers in washrooms was found likely to expose customers to over 1000 times more micro-organisms than if they were offered paper hand towel dispensers. Counts of Staphylococci were 800 times higher on jet air dryers than on hand towel dispensers, while the floors below the jet air dryers carried 20 times more bacteria than those below the paper towel dispensers.
The study, carried out in 150 washrooms in Germany’s Ruhr region, measured the extent of microbial contamination based on three types of hand drying method – jet air dryers, air dryers and paper hand towels.
Both air and surfaces are contaminated with higher levels of microorganisms when hands are dried with electric dryers iii,iv,v ,vi,vii
Professor of Medical Microbiology at the University of Leeds and Leeds Teaching Hospitals, Mark Wilcox and Emeritus Fellow, Keith Redway, of the University of Westminster have undertaken a range of lab studies examining the impact of different hand drying methods on the dispersal of microorganisms. The studies have shown that the use of warm air and jet air dryers can actually increase the number of micro-organisms on the hands after drying, as well as contaminating the washroom environment.
Washrooms equipped with paper towels for hand drying have significantly less bacterial contamination
A multisite hospital washroom studyviii in France, Italy and UK coordinated by Professor Mark Wilcox, detected levels of antibiotic-resistant bacteria – including MRSA and ESBL-resistant enterococci – more frequently in washrooms using jet air dryers. Recovery of MRSA was three times higher with jet air dryer use than with paper towels and recovery of MSSA six times higher.
These findings demonstrate how hand-drying method can affect risk of bacterial dissemination in real world settings.
Contamination of hand dryer users by splattering and aerosolization of microbes is higher when using jet air dryers.
A 2022 studyix placed participants in masks while undergoing hand drying in order to measure the potential risk of inhaling viruses. It found 89% of masks were contaminated by viruses when using jet air dryers compared with 29% when using paper towels. Contamination of hand dryer users by splattering was 10 times higher when using jet air dryers, and contamination of other washroom users was also significantly greater. In trials using jet air dryers, facemask contamination by virus actually increased at 15 minutes post-hand drying, suggesting aerosolization of small particles that remain airborne for longer.
Microorganisms can transfer beyond the washroom environment and contamination levels are significantly higher following jet air dryer use
Another study at Leeds General Infirmary, UK, found it was possible for microorganisms from poorly washed hands to be transferred onto surfaces beyond the washroom environment by hands, clothing and skin contact. Contamination levels were on average 10 times higher when drying hands with jet air dryers – likely due to the increased risk of splattering on the user’s body and clothing.
The study, published in Infection Control and Hospital Epidemiologyx, also found transfer of a virus (bacteriophage) from dried hands to items in close contact with healthcare staff and patients – such as telephones and stethoscopes. It underlines how vulnerable patients with compromised immune systems could potentially be put at risk by jet air dryers in hospital washrooms.
So, there you have it. The science shows that paper towels offer a clear advantage over electric dryers in reducing the dispersal of microorganisms both in the washroom and into the wider environment. And it seems that health authorities are starting to take note. Guidelines in Belgium, France, Germany and Scotland already recommend the use of paper towels in washing areas to support infection control and uphold the health of staff, visitors and patients.
References
i. Centres for Disease Control and Prevention https://www.cdc.gov/handwashing/why-handwashing.html
ii. http://europeantissue.com/wp-content/uploads/Eurofins-Inlab-study-presentation-2.pdf
iii. Changes in the number of different types of bacteria on the hands before and after drying using paper towel, continuous cloth roller towel, warm air dryer and jet air dryer. K. Redway, S. Fawdar, Department of Biomedical Sciences, Faculty of Science and Technology, University of Westminster, London, UK) (2010). http://www.europeantissue.com/wp-content/uploads/WU-Study-2010-Report.pdf
iv. Microbiological comparison of hand drying methods: the potential for contamination of the environment, user and bystander. E.L. Best,1 P. Parnell,1 M.H. Wilcox 1,2 – Microbiology Department, Old Medical School, Leeds General Infirmary, Leeds Teaching Hospitals NHS Trust1 & University of Leeds,2 Leeds LS1 3EX, UK. Journal Hospital Infection 2014; 88:199-206. http: //dx/doi.org/10.1016/j.jhin.2014.08.002
v. Comparison of different hand-drying methods: the potential for airborne microbe dispersal and contamination” K. Redway (Department of Biomedical Sciences, Faculty of Science and Technology, University of Westminster, London, UK) and by E.L. Best (Microbiology Department, Old Medical School, Leeds General Infirmary, Leeds Teaching Hospitals NHS Trust, Leeds UK). Journal Hospital Infection 2015; 89:215-217. http://dx.doi.org/10.1016/j.jhin.2014.11.007
vi. Evaluation of the potential for virus dispersal during hand drying: a comparison of three methods P.T. Kimmitt and K.F. Redway. Department of Biomedical Sciences, Faculty of Science and Technology, University of Westminster, London, UK. Journal of Applied Microbiology 120, 478–486 © 2015. http://onlinelibrary.wiley.com/doi/10.1111/jam.13014/full
vii. Pilot study to determine whether microbial contamination levels in hospital washrooms are associated with hand-drying method M.H. Wilcox E.L. Best, P. Parnell Microbiology, Leeds Teaching Hospitals NHS Trust & University of Leeds, Leeds, UK. Journal of Hospital infection 2017; 97 200-2003. http://www.sciencedirect.com/science/article/pii/S0195670117303894
viii. https://www.journalofhospitalinfection.com/article/S0195-6701(18)30366-9/pdf
ix. https://www.frontiersin.org/articles/10.3389/fpubh.2022.1010802/full
x. From the hospital toilet to the ward: A pilot study on microbe dispersal to multiple hospital surfaces following hand drying using a jet air dryer versus paper towels | Infection Control & Hospital Epidemiology | Cambridge Core
