Bathroom Hand Dryers Spray Fecal Bacteria on Your Hands, Study Says

Have you ever avoided public washrooms because you thought the toilet seats were dirty and door handles were germy? Then you’re really not going to like this news.

While bathroom hand dryers are more environmentally friendly and dry your hands in just a few seconds, they can also be a major growing hub for bacteria. This was confirmed by a group of researchers from the University of Connecticut, who found a pretty gross connection between bacterial viruses and bathroom hand dryers.

Bathroom Hand Dryers Spread Fecal Bacteria

The independently-funded study involved placing petri dishes either underneath hand dryers or in a neutral location in every washroom of the University of Connecticut. After doing so, the group tallied the results and found that the plates that were exposed to normal air in a bathroom setting produced only one bacterial colony (1).

The test plates that were held up to hand dryers were found to have as many as 60 different bacterial colonies on them after just a 30-second air dry. While the air coming out of the hand dryers is almost perfectly clean, it ends up pushing more dirty bathroom air around than a paper towel.

For tests conducted when the hand dryers weren’t on, the researchers found little evidence of bacteria – an average of six colonies per plate. It was only when the blowers were up and running, when the bacteria were too. The researchers checked inside the dryers to see if internal microbial buildup could be playing a part. But when they took a swab inside the dryers, bacterial counts weren’t nearly enough to account for the amount distributed by the dryers’ airflow.

Lead study author Peter Setlow, told Business Insider, “The more air ya move? The more bacteria stick…and there are a lot of bacteria in bathrooms.”

Multiple bathroom samples included the microbe Bacillus subtilis, an occupant of the human gut. But it wasn’t alone – over 62 types of diverse bacteria representing 21 species, including Staphylococcus aureus (which is associated with serious infections) were also found on the plates.

In fact, previous studies have found that “toilet plumes” from the inside of a toilet bowl can spray aerosolized feces as high as fifteen feet into the air (2). Once dispersed in the air, bathroom microbes settle on other bathroom surfaces like the floor and sink (or on your hands if you’re using a bathroom hand dryer).

The researchers did note, however, that bathroom hand dryers probably aren’t a concern for the average person. Rather, people with weakened immune systems like seniors, children, and those with immune-compromised conditions are most at risk of getting sick from hand-dryer bacteria.

Setlow himself, says he has stopped using hand dryers altogether after completing his independently-funded study.

The researchers also discovered that installing HEPA filters into the hand dryers significantly reduced the number of bacteria that the blowers dispersed. However, the filters did not entirely eliminate pathogen exposure, so there is still a small risk that someone could become infected from bathroom hand dryers fitted with HEPA filters.

Bathroom Hand Dryers or Paper Towels?

While bathroom hand dryers help deter from the un-necessary paper towel waste created in the bathroom, the recent study on hand-dryers does raise some questions.

While hand dryers are low-maintenance, cost-effective, and help out the environment, they do contain filters that need weekly cleaning. If these filters are not cleaned properly (which many of them aren’t), bacteria begins to form, which gets picked up by the air when the machine starts running. This perpetuates the uncleanliness of public washrooms, and sprays fecal bacteria onto the hands of those who decide to use bathroom hand dryers.

Paper towels on the other hand help dispose of bacteria more effectively, and they can also be used to open doors and other contaminated areas to prevent one from catching viruses. Paper towels are also not very environmentally friendly, and more often than not, people use way more than they need. This leads to unnecessary waste and over-flowing garbage bins that become breeding grounds for more bacteria that can become air-borne.

What To Use Instead?

Luckily, there’s a healthy alternative: Skip the dryers and the paper towels, and use your pants or shirt instead. You’ll be doing the environment a huge favour, and you won’t be taking any virus-causing bacterial colony home with you.