We Finally Know Why Airplane Toilets Have Blue Water

Airplanes are full of mysteries, especially to travelers with curious minds. Why can't planes go backwards? What happens if a plane is struck by lightning? When is the best time to poop on a plane? More often than not, there are simple and sensible answers that usually correspond with functionality. For example, frequent travelers may notice that the toilet water in plane lavatories is bright blue. What they may not realize is that what they're seeing isn't actually water. It may seem odd, but there is a perfectly reasonable explanation for this, and it's actually for the passengers' benefit.

The lavatory, which flight attendants call the "blue room", is a small, cramped, and uncomfortable space — so small that it can get stinky because there isn't a ton of space for odors to disperse. James Kemper invented the modern aviation toilet system in 1975, to help make the process of going to the bathroom in the sky a little less painful. Before the modern toilet, air travelers used a slosh bucket, which could cause messy problems during turbulence. Kemper's system added nonstick toilet bowls that used a vacuum suction, along with a blue liquid called SkyKem, instead of water. That's what you see in the bowl when you use the lavatory. This liquid neutralizes odors and acts as a disinfectant. Pull out this piece of trivia to impress your fellow travelers the next time you fly.

Something about airplane bathrooms that is perhaps more startling than the blue liquid is the loud flushing sound. It's so frightening that some folks believe the myth that it has enough force to suck your insides right out from your body. Travelers will be relieved to hear that this is actually impossible and has never happened. If you've ever wondered where your waste actually goes when you flush the toilet on an airplane, you'll be happy to know that there is a simple answer. When you flush your business down the airplane toilet, you'll notice that a valve opens at the bottom of the bowl. Everything in the bowl, including the blue liquid, gets vacuumed out and is stored in a closed waste tank at the back of the plane. Those contents are then vacuumed into a service truck once the flight is on the ground at its destination.

Another common misconception about airplane bathrooms is that pilots have the ability to eject waste in the middle of a flight. Worry not, that is not a function that airplanes have. This myth comes from some eyewitness accounts of "blue ice" falling from the sky and hitting homes. This blue ice is a mix of SkyKem and waste that froze at high altitudes and accidentally leaked from the closed waste system. It's gross, but don't worry, it doesn't happen often.