A study into the hygienic efficiency of the four main hand-drying systems used in washrooms found that cotton and paper towels were more effective at removing bacteria from hands than jet-air and warm air-dryers.
The study was commissioned by the European Textile Services Association (ETSA). As well as comparing how effectively the four systems removed bacteria during drying, it also examined the hygiene in the surrounding areas including both the touchable surfaces and the surrounding air.
The study, by the University of Helsinki's Hjelt Institute of Hygiene and Microbiology, found that even when hands were washed without soap, the level of bacteria removed by rubbing action of cotton and paper towels was above the minimum standards of EN1499.
Air contamination was almost non-existent around cotton and paper towel dispensers. For the other two systems, air contamination was at its highest 1m from the system and in this respect jet-air systems had a higher level of contamination than warm-air systems.
In terms of dispenser hygiene, cotton towel dispensers had the least contamination, and the jet-air dryers had the highest. Warm-air dryers had lower levels than the paper towel dispensers.
