You’ll Never Believe What Really Happens When You Flush the Toilet on an Airplane

Airplane toilets aren’t what they used to be (and, trust us, that’s a very good thing). Read on for a look at airplane toilets of the past, how we got to where we are today, and what really happens when you flush when you’re 30,000 feet up (page 5).

1. We’ve come a long way with airplane toilets

A stewardess serving drinks whilst passengers have lunch aboard a BEA Vickers Viking passenger plane
Some other air travel perks have diminished, but the toilets were pretty gross. | Fox Photos/Getty Images

World War II pilots weren’t lucky enough to have anything that even closely resembles the airplane toilets we have today. They had to use what they called a “slop bucket” (or an “Elsan”). In turbulent skies, the buckets often spilled, and on longer flights they were known to overflow, according to Telegraph.

Next: The next big thing in airplane toilet developments

2. Anotec

dirty bathroom of a commercial airliner
The bright blue liquid would help push down the waste. | wellesenterprises/iStock/Getty Images

After the slop bucket and before the toilets we have today, airplanes relied heavily on a bright blue liquid called Anotec. Upon flushing the toilet, the Anotec would help push down the waste into an on-board storage tank. According to The Things, in Anotec’s heyday, airplanes would need so much on board that they had to let fewer passengers fly.

Next: Anotec came with a few big problems. 

3. Why airplanes stopped relying on Anotec so much

Airplane toilet blue water
It was prone to leaking and falling to the ground. | Jerkcity/Wikimedia Commons

Not only was having so much Anotec on board inconvenient for a plethora or reasons, but the early toilet systems involving Anotec were also prone to leaking. This means wads of blue liquid and waste would freeze when falling from the plane at a high altitude and dangerously plummet to the ground.

According to Gizmodo, “Between 1979 and 2003, at least 27 wads of “blue ice” fell from the sky in the United States alone, impacting with enough force to tear through roofs and smash cars.”

Next: Some passengers experienced adverse reactions to Anotec. 

4. It was also harming some passengers

woman scratching her itchy back
Passengers were getting irritated skin and eyes. | Asiandelight/iStock/Getty Images

As if Anotec didn’t come with enough issues already, it also caused negative physical reactions in some of the passengers. According to The Things, one of the main ingredients in the blue liquid is bleach. Being in close quarters with a liquid that contains such high amounts of bleach began to irritate some passengers’ skin and eyes.

Next: The toilets airplanes use today

5. Today’s airplane toilets

airplane bathroom
They mostly rely on a vacuum. | VVF/iStock/Getty Images

Though today’s toilets still use some blue liquid, they rely more on a vacuum to clear passenger waste. When you flush an airplane toilet today, a pneumatic vacuum sucks the waste into a closed-waste system that’s connected to a tank. And, no, it doesn’t fall out of the sky. When the plane lands and the tank is full, a ground crew empties it.

Next: Airplane toilet secrets we bet you didn’t know

6. You can unlock a plane bathroom from the outside

Occupied bathroom sign
In case of an emergency, the flight attendant can get in there. | frontpoint/iStock/Getty Images

According to Telegraph, airplane bathrooms can actually be unlocked from the outside. “A hidden latch, sometimes behind the ‘no smoking’ sign, allows flight attendants to access a locked lavatory in an emergency,” according to the publication.

Next: The reason for ashtrays in airplane bathrooms

7. Why would an airplane bathroom need an ashtray?

No Smoking and Fasten Seat belt Sign
If someone happened to light up, they need a place to put it out. | Fominayaphot/iStock/Getty Images

Anyone who’s flown before knows smoking is strictly prohibited in an airplane. Why, then, are there often ashtrays in airplane bathrooms? Telegraph says if someone were to illegally smoke, “it’s best they have somewhere to do that rather than cause a fire by dropping it in the bin. Therefore an ashtray is a mandatory requirement in most countries.”

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