Paper towels more effective than hand dryers at removing viruses

Using paper towels to dry your hands is substantially more effective than hand dryers for removing viruses including the novel coronavirus (COVID-19), according to a new study.

According to the researchers, hand drying is important to minimise the spread of dangerous microbes - including the novel coronavirus - since failure to remove them increases transfer to environmental surfaces and increases the opportunities for transmission and spread.

For the findings, researchers from the University of Leeds in the UK investigated whether the way people dry their hands in a public toilet made a difference to the way COVID-19 is transmitted.

"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," they noted.

According to the researchers, four volunteers simulated contamination of their hands/gloved hands using a bacteriophage (which is a virus that infects bacteria - and so is harmless to humans).

Their hands were not washed after contamination - this was to simulate poorly/inadequately washed hands. Hands were dried using either paper towels (PT) or a jet air dryer (JAD).

Each volunteer wore an apron, to enable measurement of body/clothing contamination during hand drying. Hand drying was performed in a hospital public toilet and, after exiting, samples were collected from public and ward areas.

The team found that both jet air dryer and paper towels methods statistically significantly reduced virus contamination of hands.

For 10 out of 11 surfaces, significantly greater environmental contamination was detected after jet air dryer versus paper towels use. Average surface contamination following hand contact was more than 10 times higher after jet air dryer versus paper towels use.

According to the researchers, viral dispersal to apron/clothing was 5-fold higher with jet air dryer compared to paper towels.

This suggests transference of microbes to environmental surfaces can occur directly from hands that remain contaminated after hand drying, but also indirectly from a person's body that has itself been contaminated during hand drying.

"There are clear differences, according to the hand drying method, in the residual microbial contamination of the participant's hands and body," the authors said.

"As public toilets are used by patients, visitors and staff, the hand drying method is chosen have the potential to increase (using jet dryers) or reduce (using paper towels) pathogen transmission in hospital settings," the authors wrote.