Bathroom

The door handle is the dirtiest fixture in the bathroom

One thing we hear all the time from friends and family is the lengths they will go not to touch things in the restroom. One of the most common strategies involves using a paper towel to open the bathroom door. People seem to be genuinely afraid of the door handle. Rachel recently heard a woman pushing a public bathroom door open with her elbow repeatedly say “touching the door handle in a bathroom will make you sick.” Once Rachel left the bathroom, she saw that same woman smoking. Hmm. That’s interesting.

Let’s take a breather and think this through. It’s important to think about why we assume certain things are “dirty” or can harbor infection. In the case of the bathroom, it’s because we know something “dirty” occurs there. Picture a bathroom in your head. We bet you didn’t picture a sparkling clean room, shiny and bright. We bet you pictured a dark, dank, filthy room. But it’s important to remember that that’s your impression. It’s not necessarily based on fact.

The truth is that the actual dirtiness of an object or place comes down to two factors: (1) how many people have touched it with dirty hands, and (2) how often it is cleaned. With respect to the door handle of the bathroom, we can’t vouch for (2), but we bet it’s more often than the door handle in your office. But here’s the thing, as for (1), the door handle in the bathroom is touched far more often by clean hands—they’ve just been washed—than dirty.

In fact, the door handle seems to be one of the cleanest things in the bathroom. Don’t take our word for it; it’s been studied. Dr. Chuck Gerba, known also as “Dr. Germ,” has conducted a number of studies in this area. Someone had to, we guess. In one study, he found that toilet seats and door handles are the cleanest surfaces in public bathrooms. Amazing, but true! The bathroom floor was the dirtiest thing in the bathroom by a long shot, and often contained more than two million bacteria per square inch. So don’t put your purse or briefcase on the floor (which we bet lots of you do)!

Faucets and sinks are also worse than the door handles or toilets. That’s because people don’t wash their hands before touching those. Again, this has been studied. It’s not our guess. Think back to those rules we mentioned before. Think about the many things that are touched by lots of dirty hands and never cleaned. Things like elevator buttons. Shopping carts. Money machine buttons. Supermarket self-serve checkout machines. Playground equipment. Hotel room remotes.

Should we continue?

We don’t say this to make you crazy. After all, many of you are touching these things all the time and will not get sick as a result.

Air dryers will keep your hands cleaner than paper towels

One of the best things about writing a book like this is that we get to discover some amazing science being done by people we would never otherwise hear of. One of those people is Dr. Keith Redway of the School of Biomedical Sciences at the University of Westminster in London. Believe us when we tell you that he is the man when it comes to drying your hands in the bathroom. Sure, other people have done some work in the area, but no one else—to our knowledge—has dedicated himself to the truly important question of how best to dry your hands in a public restroom. Don’t take our word for it. Go look him up.

Why is Dr. Redway’s work important? Well, how many times have you finished washing your hands at the sink and been presented with the impossible choice of whether to use the hot air dryer or paper towels? From what we see online and hear from many of you, the overwhelming choice would be to use the air dryer. People believe it’s more sanitary than paper towels. After all, you need to touch nothing to use it. Many air dryers even have claims about being more sanitary printed right on the machine.

But is that true? In a series of experiments, Dr. Redway and a colleague of his decided to find out. For each of these studies, they compared different paper towels, warm air dryers, and newer jet air dryers.

First, they looked at how well each of these methods achieved dryness. After all, that is the primary purpose of drying your hands. Specifically, they measured the amount of water remaining on the hands at different times up to one minute. They found that all five types of paper towels and the jet air dryer achieved 90 percent dryness by ten seconds. The warm air dryer took much longer to achieve the same effect. Make of that what you will.

The next study was where it gets interesting. How much does using each of these drying mechanisms affect germs on your hands? They took twenty people and measured the numbers and types of bacteria on their hands both before and after using two types of paper towels and the warm air and jet air dryer. Both types of paper towels reduced the number of all types of bacteria on both the palms and fingertips. Warm air dryers, on the other hand, actually increased the number of all types of bacteria and the jet air dryer increased the number of most types of bacteria on both the palms and fingertips. The paper towels were the obvious winners in terms of reducing bacteria on hands.

But they weren’t done yet. For their next study, they took ten people and artificially contaminated their hands with a yeast suspension. Again, they had them dry with two types of paper towels and the warm air and jet air dryer. The point of this was to see how these drying methods contaminated the rest of the environment. They found that the jet air dryer dispersed the contaminant over two meters from where the dryer was located. The warm air dryer was slightly worse than the paper towels in that it dispersed more contaminant, but only directly below the dryer.

There’s more. In a final experiment, they went to sixteen public restrooms in a London rail station and swabbed the jet air dryers to see what kind of bacteria was there to be potentially spread around the room and onto hands. They also measured what was contained in air emitted from them over a ten-second period. They found a large number of bacteria, some of which were potential pathogens.

So to sum it up, paper towels dried just as well as anything, removed more bacteria that were on the hands already, and did not contaminate other parts of the bathroom. Seems like an easy decision on which to use next time.

We should note that other work has been done comparing air dryers to paper towels. Some of the work agrees with Dr. Redway’s findings. Some of it finds less of a difference between the methods. We should also note that Dr. Redway has often been funded by the paper towel industry in his research. But we can find no fault with his methods, and no one seems to have the single-mindedness of his calling.

The idea that hot air or jet air dryers are superior (in cleanliness or drying ability) is simply a myth.