Science decides

The third pillar is air hygiene. Two well-researched germ-spreaders are found in washrooms that release large quantities of germs into the indoor air. One is the toilet flush – when flushing, the toilet lid should always be closed to minimise the risk of infection via aerosols. The other germ-spreaders are electric airflow dryers: when actuated, these powerfully distribute germ containing air via aerosol in the room^3,7,8. Even directly after washing your hands, these are not completely free of germs. In addition to the bacteria in our skin flora, lingering viruses can, if hands are not washed properly, also enter the indoor air via airflow dryers. Since even just a few germs are sufficient for infection with many viral cold- or diarrhoea pathogens, and because viruses remain in the indoor air in an aerosol for several hours, a risk of infection can also arise in this way⁹.

Many germs could be detected after deposition on horizontal surfaces in the immediate vicinity of airflow dryers (e.g. on the floor). The highest proportion of germs was found in the immediate vicinity (in approx. 1 m radius) of the airflow dryer⁹. In contrast to various electric fan dryers, which generate a germ-containing aerosol with high air speeds, this danger does not exist when drying hands with paper towels. Therefore, paper towels are also the better choice from the point of view of air hygiene. Paper towels produce almost no aerosol containing germs, even when drying poorly washed hands^10,11.

The fourth pillar is user-friendliness. The high air velocity of air flow dryers is achieved by very high engine speeds, which lead to very high noise levels. According to studies, these devices can reach a volume of 94 dB. In addition to the spread of germs from such devices, this volume is also a reason why, according to the Robert Koch Institute, jet air dryers should not be used in medical facilities¹⁰. Due to their smaller size, children or people in wheelchairs have their heads closer to the jet air dryer, resulting in even higher noise levels of up to 115 dB¹¹. The Federal Environment Agency also comes to the conclusion that these dryers pose a medium hearing hazard for children¹².

Die vierte Säule ist die Anwenderfreundlichkeit. Die hohen Luftgeschwindigkeiten von Luftstromtrocknern werden durch sehr hohe Motordrehzahlen erreicht, welche zu sehr großen Lautstärken führen. Studien zufolge können diese Geräte eine Lautstärke von 94 dB erreichen. Neben der Keimverbreitung solcher Geräte ist auch diese Lautstärke ein Grund, weshalb die Jet-Lufttrockner laut Robert Koch-Institut nicht in medizinischen Einrichtungen eingesetzt werden sollten¹⁰. Aufgrund ihrer geringeren Größe sind die Köpfe von Kindern oder Menschen, welche auf einen Rollstuhl angewiesen sind, näher am Jet-Lufttrockner, was sogar zu noch höheren Geräuschpegeln von bis zu 115 dB führt¹¹. So kommt auch das Umweltbundesamt zu dem Ergebnis, dass diese Trockner für Kinder eine mittlere Gehörgefährdung darstellen ¹².

115 dB is the noise level that jet air dryers can reach¹¹

In addition to the low volume during use, paper towels also offer very good accessibility. They do not require constant overhead handling, as with airflow dryers or cotton roll dispensers, and dangerous leaning out of the wheelchair, e.g. to operate an air flow dryer, in which the hands have to be put in from above, is eliminated.