ECJ EUROPEAN Cleaning Journal

A new study conducted in the UK has concluded that electric hand dryers spread microbes much more than paper hand towels - despite the advent of newer models.

Carried out by a team at the Leeds Institute of Medical Research, Faculty of Medicine and Health, University of Leeds and Department of Microbiology, Leeds Teaching Hospitals NHS Trust, the research was supported by the ETS, the European Tissue Paper Industry Association.

Three different hand drying methods were compared. The team in Leeds examined the impact on the formation of droplets and aerosols containing viruses, surface contamination and person-to-person exposure from paper hand towels and two jet air dryer designs.

They used both a food dye solution and bacteriophage (virus) suspension to visually and quantitatively investigate the potential of each of the three options to disperse water droplets in the washroom environment, potentially contaminating surfaces, the user and a bystander.

The researchers also investigated whether microbes aerosolised during hand drying can contaminate the facemasks of others sharing the same space, thereby mimicking the risk of breathing in viruses for up to 30 minutes after hand drying.

The scientists concluded that electric hand dryers spread microbes more than tissue paper. The highest level of microbe contaminated droplets on the floor and walls was observed using the electric hand dryer method. The research found that microbes can remain airborne for up to 30 minutes after dryer use, with wall contamination levels up to 78 times higher compared to paper towels.

The study showed significantly less splattering contamination of both masks and torso when using paper towels than electric dryers. Mask contamination of users in the hand drying area after 15 minutes showed that aerosolisation was up to 100x higher with dryers than with paper hand towels. Contamination of the masks of standby users at 1m was up to 10x higher with electric dryers than with paper towels after 30 minutes.

There was also significantly less surface contamination with paper towels which reduce the risk of touch-transfer on objects such as door handles.

To read the full study click here.