Comparative evaluation of the hygienic efficacy of an ultra-rapid hand dryer vs conventional warm air hand dryers

Abstract

Aims:To compare an ultra-rapid hand dryer against warm air dryers, with regard to: (A) bacterial transfer after drying and (B) the impact on bacterial numbers of rubbing hands during dryer use.Methods and Results:The Airblade™ dryer (Dyson Ltd) uses two air ‘knives’ to strip water from still hands, whereas conventional dryers use warm air to evaporate moisture whilst hands are rubbed together. These approaches were compared using 14 volunteers; the Airblade™ and two types of warm air dryer. In study (A), hands were contaminated by handling meat and then washed in a standardized manner. After dryer use, fingers were pressed onto foil and transfer of residual bacteria enumerated. Transfers of 0–107 CFU per five fingers were observed. For a drying time of 10 s, the Airblade™ led to significantly less bacterial transfer than the other dryers (P<0·05; range 0·0003–0·0015). When the latter were used for 30–35 s, the trend was for the Airblade to still perform better, but differences were not significant (P>0·05, range 0·1317–0·4099). In study (B), drying was performed ± hand rubbing. Contact plates enumerated bacteria transferred from palms, fingers and fingertips before and after drying. When keeping hands still, there was no statistical difference between dryers, and reduction in the numbers released was almost as high as with paper towels. Rubbing when using the warm air dryers inhibited an overall reduction in bacterial numbers on the skin (P < 0·05).Conclusions:Effective hand drying is important for reducing transfer of commensals or remaining contaminants to surfaces. Rubbing hands during warm air drying can counteract the reduction in bacterial numbers accrued during handwashing.Significance and Impact of the Study:The Airblade™ was superior to the warm air dryers for reducing bacterial transfer. Its short, 10 s drying time should encourage greater compliance with hand drying and thus help reduce the spread of infectious agents via hands.

The Hygienic Efficacy of Different Hand-Drying Methods: A Review of the Evidence

“…49 It might be that rubbing hands causes bacteria to migrate from the hair follicles to the skin surface. 35,44 Many studies have found friction to be a key component in hand drying for removing contamination. For example, Sprunt et al 63 and Coates et al 32 reported that bacteria were removed from washed hands by the mechanical abrasive action of drying with paper towels.…”

“…Drying with hot air dryers while rubbing hands was less effective than using paper towels. Snelling et al 35 compared a jet air dryer against 2 models of hot air dryers with regard to bacterial transfer after drying and the effect of rubbing hands during dryer use. For a drying time of 10 seconds, both hot air dryers were associated with higher levels of bacteria transfer than when no dryer was used at all.…”

“…35 Lack of attention to this aspect may negate the benefits of careful hand washing in health care. So far, little research has been conducted to examine the contribution that proper hand drying makes to the overall effectiveness of hand hygiene practices.…”

Händehygiene in Einrichtungen des Gesundheitswesens

“…Allerdings war nach vorher durchgeführter Händedesinfektion keine erhöhte Translokation durch Heiß-lufttrockner nachweisbar [228,229]. Nach Händewaschung wird durch Papier-oder Textilhandtuch signifikant mehr Restflora als durch Heißlufttrockner entfernt [230][231][232]. Schließlich ist bei der Auswahl des Trocknungssystems zu berück-sichtigen, dass Nutzer bezüglich Komfort und Nutzerfreundlichkeit Einmalhandtü-cher gegenüber Heißlufttrocknern bevorzugen [226] und die Lärmbelastung bei "jet air" Trocknern in 0,5 m Entfernung 94 dB erreicht [224].…”

Environmental and Economic Perspectives in the Analysis of Two Options for Hand Drying At an University Campus

“…Most of the international studies focused on the hygienic efficacy of different hand drying methods [9,10,12,[36][37][38][39][40]. When analyzing hand drying options, hygiene is also an aspect of interest, but it was not considered herein.…”