The Dyson Conspiracy: Why hand dryers are working against you

Envision sitting in your favorite local coffee shop, drinking cold brew with your friends, when one of them gets up to use the restroom and returns with damp hands.

“They don’t offer paper towels, and I don’t trust hot air dryers, so I’m just letting my hands air-dry,” they say as you look on with horror as they grab a Stevia packet from in front of you.

This friend is making multiple mistakes. First of all, Stevia granules mix poorly with cold brew. Secondly, not drying your hands after using the restroom turns them into a petri dish for bacteria. Harmful bacteria thrive in moist conditions, so if you’re allowing your hands to “air dry” half an hour after using the restroom, you’re essentially negating the effects of washing your hands.

Yet, there is widespread ambivalence about using the hot air dryers in public restrooms. In a 2008 episode of the Big Bang Theory, Sheldon Cooper laments the switch from paper towels to hot air dryers at his work. “Hot air blowers are incubators and spewers of bacteria and pestilence. Frankly, it’d be more hygienic if they just had a plague-infested gibbon sneeze my hands dry,” he said.

A viral Facebook post a few months ago featured a grotesque photo of cultures that the author ostensibly retrieved from a Dyson hand-dryer. The post read, “DO NOT EVER dry your hands in those things again. This is the several strains of possible pathogenic fungi and bacteria that you’re swirling around your hands, and you think you’re walking out with clean hands.”

Researchers suggest that those who use hot air dryers are more vulnerable to germs because most people don’t properly wash their hands. While over 90 percent of Americans reported that they always wash their hands after using the restroom, only approximately 80 percent of Americans actually do in repeated experiments, with women consistently washing their hands more often than men. Worse yet, one Michigan State University study found that over 20 percent of participants didn’t bother using soap, and only 5 percent of participants washed their hands the recommended 15 seconds or more.

And because people aren’t adequately removing the bacteria from their hands, the hot air dryers spew germs onto the floor and then back onto subsequent users’ hands. Additionally, bacteria can be blown across a restroom when flushing if it is a single-use bathroom.

A review of the scientific literature posted on the Center for Disease and Control’s website concluded that hot air dryers are significantly less hygienic than paper towels. It’s worth considering that in places where hygiene is of utmost concern, like health care facilities, hot air dryers are strongly recommended against. Some of the experiments analyzed in the review even discovered that there were more bacteria on people’s hands after drying them with a hot air dryer than before drying their hands, while all studies reported that the amount of bacteria on people’s hands were reduced after using paper towels.

Some people might ask about the efficacy of jet air dryers like Dyson over conventional hot air dryers. In 2008, Dyson received public health accreditation from the Royal Society of Public Health, a private health awareness charity in Great Britain. In 2016, a study from the Journal of Applied Microbiology discovered that jet air dryers spread 1,300 times more germs in an affected area than a paper towel, compared to conventional warm air dryers 60-times spread. Another study, funded by the Big Paper Towel lobby, found that jet air dryers spread germs at 27 times the rate of paper towels. Conversely, a study funded by Dyson found that jet air dryers were more effective at removing bacteria than paper towels.

However, in most public bathrooms, the amount of harmful bacteria or viruses circulating are not high enough for hot air dryers or jet air dryers to be dangerous. In settings where there are massive pathogenic loads, like a restroom that is only cleaned once a blue moon, or during times of disease outbreaks, like flu season, it may be more critical to forgo hot air dryers altogether.

Realistically, what is paramount is washing your hands semi-adequately and drying them somehow, even if it involves shaking your hands vigorously around the public restroom sink after you’re done rinsing them. The reason why it’s so important to have dry hands is that washing them with soap and water, even hot water, doesn’t actually kill pathogens. Rather, rinsing your hands with soap and water removes them from your hands and sends them down the sink. However, pathogens are more likely to linger on your hands if they’re still damp. You can also opt for an alcohol-based hand sanitizer, which does indeed kill most harmful pathogens.

Note that you should be apprehensive about questioning the merits of jet air dryers like Dyson. The woman who wrote the viral Facebook post disparaging Dyson air dryers purportedly received death threats for it.