What Is a Chemical Toilet?

J.L. Drede

A chemical toilet is a special toilet that uses chemicals to treat and deodorize waste. It is different than a traditional toilet used in most homes, which uses water to flush the waste away. These toilets are usually found in places where traditional plumbing is not possible.

Many times, the contents of chemical toilets can not be dumped into a septic tank.
Many times, the contents of chemical toilets can not be dumped into a septic tank.

In every chemical toilet there is a reservoir that stores special chemicals, typically ammonia compounds, that work to break down human waste. While the chemicals in the toilet do make the waste relatively odorless, they do not completely disinfect the waste. Human waste retrieved from this toilet can still harbor dangerous bacteria and other microbes.

Chemical toilets are usually installed on commercial aircraft.
Chemical toilets are usually installed on commercial aircraft.

Reservoirs in chemical toilets are emptied and replaced once they reach their fill. Many times the contents have to be dumped at special sites since they cannot be dumped into the general sewage system or into most septic tanks because of the chemicals they utilize.

Since a chemical toilet is often a waterless toilet, they are very convenient to use in areas where water cannot be easily accessed or is in limited supply. All port-a-potty toilets are chemical toilets. These portable bathrooms are very common on construction sites where plumbing has not yet been installed or at large concerts and other events where the number of people attending could quickly overwhelm the built-in bathrooms.

Some remote cabins use chemical toilets, as do many RVs and mobile campers. Many RV parks even have specially-approved dumping sites made specifically for RV owners to dispose of their full toilet tanks. These tanks are usually fairly small and can be dumped by hand.

Airplanes use a variation of the chemical toilet called a vacuum toilet. This waterless toilet employs both a powerful vacuum flush that removes all the waste left in the toilet. A small portion of the chemical agent also passes through the bowl when it is flushed to kill odor. A vacuum-assisted toilet is used in airplanes because using water would be impractical; turbulence or any sudden movements by the plane could make the water splash out.

The waste from the airplane toilet is stored in a chemical tank inside the plane. Although urban legends exist about planes dumping waste out of plane while in flight, this is not the case. In reality, the chemical tank is emptied and filled again by a special service cart after the plane lands at the airport.

Chemical toilets that are not properly maintained can be a breeding ground for insects.
Chemical toilets that are not properly maintained can be a breeding ground for insects.

You might also Like

Readers Also Love

Discussion Comments


I’m always afraid to use the chemical toilets at outdoor concerts. There are so many people walking around, crowded together and pushing. I worry that if I’m in there on the toilet, a sudden surge of people could push into the structure and topple me over.

I have seen young mischievous kids pushing over port-a-potties before at such events. I have a horror of old excrement flowing out onto me as I struggle to escape the sideways bathroom. My clothes would be soiled, I would have to walk through the crowd like that, and I would have to drive home infected with who knows what.


I often go to a large state park with many rest areas. It seems that several of them are always out of order, but port-a-potties are always provided outside of the brick buildings.

When I first used one, I thought it strange that there was no water in the bowl. I did not know that chemicals were used. I saw the big lever to flush with, and when I pulled it, a blue substance came out of holes in the bowl and washed down the drain.

It’s good to know that there are chemicals working on the sewage stored in the port-a-potty. Without them, I’m sure the smell would be unbearable.


@MrMoody - Whenever there is a big public event like a Fourth of July celebration in a public park where there are no public toilets around, the porta-a-potty buildings are lined up everywhere.

Like you, I try to go to the bathroom before attending the event so that I’m not forced to use these toilets. I’m not knocking them; they are better than nothing, and when you have to go, you have to go.

Personally I think that the toilets in airplanes, which use vacuum technology plus chemicals, are more effective in decomposition and killing odors.


While I have used a porta-a-potty toilet before I do take issue with the idea that these toilets are essentially odorless. That certainly has not been my experience anyway.

I try to avoid these portable toilets for a number of reasons, including basic hygiene. I didn’t realize that they used chemicals, and while they may in fact be beneficial in decomposing human waste they don’t render the portable toilet totally clean and odor free in my opinion. I suppose they are better than nothing in some instances however.

Post your comments
Forgot password?