Do Jet Hand Dryers Actually Release a Cloud of Germs? The Answer is Both Yes and No

The last thing anyone desires in a public restroom is additional germs, yet the method they choose to dry their hands might be contributing to the spread.

Recent studies examining the impact of hand-washing, hand dryers, and germs suggest that, in certain scenarios, traditional methods might be superior.

A study released on Feb. 9, 2018, in the journal Applied and Environmental Microbiology revealed that hand dryers, which draw in restroom air teeming with microbes and debris, then expel it at high speeds, significantly increase people's exposure to microorganisms. This conclusion was drawn after analyzing samples from both ambient and dryer-blown bathroom air.

By exposing petri dishes to both types of air, researchers observed that without hand dryers in operation, only six bacterial colonies developed. However, when the dryers were active, the number of colonies surged to as many as 60 per plate, including Staphylococcus aureus, a bacterium known to cause severe infections.

Just a Slight Breeze

A separate study, published on Nov. 30, 2015, in the Journal of Applied Microbiology, examined various hand-drying techniques and their impact on the spread of germs.

Researchers found that jet air dryers, often marketed for their hygiene benefits, can disperse viruses up to 10 feet (3 meters) away. These dryers, activated by placing hands vertically inside, emit powerful air jets that spread viral plaques—clusters of viruses—at a rate 1,300 times higher than paper towels. The study did not explore the spread of bacteria, which are larger than viruses. 

The results were documented after participants immersed gloved hands in a solution containing a harmless virus. They shook off excess liquid and employed one of three drying techniques: paper towels, warm air dryers, or jet dryers. Air samples were gathered at various distances from each dryer type, and petri dishes captured viruses on nearby surfaces. Ultimately, the jet air dryer dispersed viruses the most extensively.

The findings hold considerable importance, not just for those wary of increasing germs in public restrooms, but also for hospitals dedicated to patient health.

Dyson, the manufacturer of the popular Airblade jet air dryers, disputes these claims. In 2008, their dryer became the first to receive accreditation from the Royal Society for Public Health. Dyson highlights 2015 research indicating that up to 88 percent of unused paper towels in the U.S. harbor bacteria, which can transfer to hands.

Dyson also argues that the Journal of Applied Microbiology study artificially exaggerated germ levels. In real-world scenarios, the company asserts, most individuals wouldn’t have the same high concentration of viruses on their hands as used in the study, nor would they insert unwashed, virus-laden hands into a jet dryer without prior rinsing and cleaning. 

There Is Another Path

What’s the optimal approach for hand washers? Experts remain divided. An April 2016 study in Infection Control & Hospital Epidemiology compared the CDC’s three-step handwashing method to the WHO’s six-step strategy. Observing healthcare professionals, the study found the six-step method, which includes alcohol-based hand rubs, eliminated more bacteria. The CDC has since updated its guidelines to a 5-step process.

The study highlighted compliance challenges with the six-step method. "Only 65 percent of participants completed the full hand hygiene process, despite having instructions and being monitored," noted Jacqui Reilly, the study’s lead author. "This calls for further research."

For those needing to dry their hands amid the ongoing debate, the safest choice might be a traditional paper towel dispenser followed by generous use of hand sanitizer. And remember, always start with a thorough scrub using soap.