Paper towels are better than hand dryers at removing viruses such as coronavirus, new research shows.
For people who have not washed their hands properly, using paper towels is substantially more effective than hand dryers at removing the germs on their hands.
Scientists say hand drying is important to minimise the spread of dangerous microbes including the novel coronavirus.
Failure to remove them increases transfer to other surfaces and opportunities for it to spread and be passed onto other people.
The new UK study investigated whether the way you dry your hands in a public toilet made a difference to virus transmission in a hospital environment.
Dr Ines Moura, from the University of Leeds, said: "We believe that our results are relevant to the control of the novel coronavirus that is spreading at pace worldwide.
"Paper towels should be the preferred way to dry hands after washing and so reduce the risk of virus contamination and spread."
Researchers also noted their findings have particular importance since there has been a general migration from use of paper towels to hand dryers in many settings and areas of the world, especially within UK healthcare environments.
Yet both UK NHS and WHO hand washing guidelines recommend use of a paper towel to dry hands and also using a paper towel to turn off the tap.
In their research, four volunteers simulated contamination of their hands or gloved hands using a bacteriophage which is a virus that infects bacteria and is harmless to humans.
Their hands were not washed after contamination to simulate poorly or inadequately washed hands.
Hands were dried using either paper towels or a hand dryer and each volunteer wore an apron to measure the level of contamination to the body and clothes while hand drying.
They dried their hands in a hospital public toilet and after leaving, samples were collected from public and ward areas.
Scientists tested surface sites after contact with their hands or apron, including doors, stairs, handrails, lift buttons, phones, intercom buttons and chairs in public and ward areas.
This also included stethoscope tubing, stethoscope head and chest pieces and the aprons themselves.
Findings revealed both hand dryers and paper towel methods statistically significantly reduced virus contamination of hands.
But for ten out of 11 surfaces, significantly more environmental contamination was detected after using a hand dryer compared with paper towels.
All surfaces tested following the use of hand dryers showed phage contamination, a type of virus, compared with only six surfaces after paper towel use.
The average surface contamination following hand contact was more than ten times higher after drying hands with a hand dryer than with paper towels and viral dispersal to the apron and clothing was five times higher.
In the experiment, volunteers were also asked to fold their arms across their chest while using the apron before resting on the arms of a chair.
Results showed transfer from the apron to armchairs was detected only after using the hand dryer.
This suggests microbes can not only be transferred to environmental surfaces directly from hands that remain contaminated after hand drying but also indirectly from from a person's body that has itself been contaminated during hand drying.
Professor Mark Wilcox, from the University of Leeds, said: "There are clear differences, according to hand drying method, in the residual microbial contamination of the subject's hands and body.
"Crucially, these differences in contamination translate into significantly greater levels of microbe contamination after jet air drying versus paper towel use from hands and body beyond the toilet or washroom.
"As public toilets are used by patients, visitors and staff, the hand drying method chosen has the potential to increase, using jet dryers, or reduce, using paper towels, pathogen transmission in hospital settings."
Findings were published in an abstracts book by the European Congress on Clinical Microbiology and Infectious Diseases (ECCMID).
The research was due to be presented at the ECCMID in Paris which was cancelled due to coronavirus.
