Electric Hand Dryers Serve as a Microbial Reservoir for Contamination.

Electric hand dryers, particularly jet-air dryers, are a relatively new method of drying hands and claim to be a more efficient and sterile method than using paper towels. Our purpose for performing this research was to determine whether electric hand dryers in public restrooms are antiseptic, or if they could be a source of bacterial contamination to your hands during drying. Initially, restrooms at Weber State University were selected that had a high frequency of foot traffic, making them good sampling locations. Testing was done in men's and women's restrooms in three buildings on campus, testing four bathrooms for each group in each building. Samples were collected by swabbing a 25-cm² area of the top, middle, and bottom of the hand dryer chamber using a 3M Quickswab. Pour plates using TSA were used to enumerate samples. Plate counts were determined at 48 hours after incubation at 37°C. Results showed the bottom of the dryer chamber in both the men's and women's restrooms had the most bacterial contamination, with an average of 311 CFU/25 cm² in the men's rooms and an average of 299 CFU/25 cm² in the women's. The middle section was the second most contaminated averaging 144 CFU/25 cm² for men and 145 CFU/25 cm² for women, while the top section was the least contaminated, averaging 107 CFU/25 cm² for men and 51 CFU/25 cm² for women. Results showed that electric hand dryers can serve as a source of bacterial contamination after hand washing. The overall level of bacterial contamination was higher in hand dryers in men's restrooms. As a preventative measure, the inside of these dryers should be cleaned on a daily basis to prevent people from contaminating their hands immediately after washing them, thus reducing the spread of bacteria. [ABSTRACT FROM AUTHOR]