How does a composting toilet work? (2023)

Usage and functioningof composting toilets

Have you ever wondered what a composting toilet is and how it works? Why should you get one for your travels? In this blog post, we have summarized the most important aspects of it.

Chances are high that you looking for more information regarding composting toilets when you read these words. The good thing is: You are absolutely in the right spot! In this article,you will learn what a composting toilet is, how to use it and how it functions.

Afterwards, you will hopefully understand why we are such big fans of these products and have created our own brand, to help even more people to enjoy the benefits of portable composting toilets, i.e. spending more time in places they love!

TL;DR: A composting toiletworks as follows:

  1. You sit down
  2. A separator divides liquids and solids in two separatecontainers:
    This separationis the firststep toprevent smells
  3. You add a carbon-rich cover material (litter) to your solids after each use:
    This cover material is the secondstep toprevent smells
  4. There is no flushing / water usage and no chemicals
  5. You can dispose liquids and solids separately once filled up

How does a composting toilet work? (1)

1.Theconcept of a composting toilet

A composting toilet separates your urine from your solids. That is why we also refer to it as a separating toilet.And it does this in a very simple way:

With the so-called urine separator.

Why separate?Becausenot separating, i.e. mixing, liquids and solids, as with a normal toiletlike at home or a camping / chemical toilet, creates all of the things that you want to avoid: Smell, weight (as you use water to flush), short emptying cycles and unpleasant emptying procedures. By separating, you are avoiding all of these problems and make life much more convenient.

First things first: You need to sit down when using a composting toilet, otherwise the whole system won't work.

(Video) Composting Toilets: How Do They Work?

The composting toilet consists of onlythree main elements:

How does a composting toilet work? (2)

  • Urine separator (separating toilet insert)
  • Solids container or bucket, lined with a (compostable) plastic bag
  • Urine canister (This can also be replaced by a hose totransport the urine into a larger tank)

In addition, you will of course need an appropriate box and a toilet seat.

Liquids and solidsare collected separately in the composting toilet. Typically, the solid matter in a bucket in the back (lined with a plastic bag) and the urine, in a canister, in the front. Those two can then also be individually be emptied.

How does a composting toilet work? (3)

Sometimes, youhear the term "dry toilets". These are also waterless toilets but they lack the separation. Instead they collect both the liquids and the solids in the same bucket. That still gives you many of the issues listed above and therefore we prefer the separation method.

Important reminder:To ensure that the separation works according to plan, you must use the toilet in aseatedposition. Otherwise, proper separation is not guaranteed. This is because the urine separator is anatomically designed for a person sitting down.

2.A composting toilet doesn't smell

As you learned in the first section, the separating mechanism creates a variety of advantages. One of the biggest is surely the smell. Where does the normal smell of a toilet go?

Well, it's actually pretty simple.Nature has already provided a mechanism for the separation of liquids and solids in most living things and for a good reason.

Part A: Urine by itself is pretty harmless and doesn't really smell much. It actually contains a lot of nutrients, such as nitrogen (high levels), phosphorous and potassium. It is thus an excellent fertilizer.

In the context of the composting toilet, it should be mentioned again here that urine only begins to decompose after a long period of storage and thus the odor formation.

(Video) COMPOSTING TOILETS 101: Separett Review & How To Empty It

The well-known urine smell is primarily caused by the combination with water, especially with the lime dissolved in it. Another factor responsible for the odor is the urine scale that builds up over time.

So the longer urine is collected, the more likely it is that odor will be perceived. For this reason, most urine-diverting toilets have a maximum of one 10-litre canister, which lasts for about 2-4 days.

How does a composting toilet work? (4)

Part B: Your poo is also pretty harmless by itself. The main thing here is that you want to dry the poo as quickly as possible because once it is dried, the smell is gone.The drying of solids is the open secret behind a functioningcompostingtoilet.

You can achieve this in two ways:

1. Use a cover litter material, such as saw dust or small pet litter to speed up the drying process. The material should always contain some amount of carbon. All the moisture is absorbed by the litter and released through the fibers so that everything can dry off.However, if the litter is collected for a longer period of time and if you travel in hotter climates, condensation will form over time.

This can be prevented or regulated by leaving the lid of thecompostingtoilet open from time to time or by using a fan. This allows the moisture to evaporate.

2. A fan can be used as a support or alternative to the litter. This ventilates the moist warm air outside and allows thesolids to dry.The fan also removes freshly formed odors, so that the overall odor formation is somewhat reduced.By using a fan, you can collect for longer. Without a fan, the disposal intervals are somewhat shorter.

3. Why does a composting toilet not require water?

As previously mentioned, a composting toilet is also always a dry toilet. This means that it does not need water for flushing.

Your solids fall directly into the solids bucket due to gravity without touching the urine separator. The bucket is also used to dry and store your stool.

The urine is fed through the funnel-like design of thecompostingtoilet insert at the front into the urine canister or with a hose into a urine tank. Here, too, you don't need water for flushing.

The big advantage here is that with a urine-diverting toilet you don't waste precious drinking water for flushing, which you have to dispose of afterwards.

(Video) Composting Toilets: How do they work?

4.Why does a composting toilet not require chemicals?

Sinceyou separate your solids and urine, you don't need chemicals like a regular cassette toilet.

Why is that?

The chemicals incassette toilets have to be used because both liquids and solids are mixed together. This creates a lot of unpleasant smells and by adding certain chemicals, this smell is neutralized.

5. What kind of litter material should I use?

As you learned in the beginning, the solids are collected in a separate container. This is always lined with a plastic bag in which the solids are dropped.

How does a composting toilet work? (5)

(Video) How To Use A Composting Toilet

Before the first use, you should add two scoops of litter material, e.g. small pet litter or saw dust, to the bottom of the container.

Then, after each use, depending on the amount of solids that you dropped, add one to three scoops of litter material to cover up your recent business.

Regarding the material itself, we wrote a separate blog post on that topic. Have a look here and read about the different litter options for your composting toilet.

That's it, pretty easy!

6. How doyou dispose waste froma composting toilet?

It's rather simplebecause you can empty the twoindependently of each other:

  • Solids (possibly with your litter, e.g. saw dust)
  • Urine canister

You can either dispose of your solids ina compost* (if you have one) or simply add them to your regularhouseholdtrash (check your local regulations,since some states have specific rules). Think of it as a diaper or dog waste bag.

The urine can be poured down any public (regular) toilet or sewage system.Otherwise, it can alsobe diluted andused as fertilizer* in your garden.

Summarized: By usinga composting toilet, younolonger need dedicateddisposal stationsfor your cassette toilets.Therefore you can travel for much longer trips off-the-grid and properly enjoy nature and the outdoors.

Let's face it: The composting toilet is the toilet of the future. It saves resources and is sustainable. Plus it gives you all the freedom you want for your travels!

Interested? Have a look at our collection of high-quality and comfortable composting toilets.

(Video) Airhead Composting Toilet | Our Favorite Upgrade for Full Time RV Living

*pleasefollow the regulations of your municipality andbe carefulifyou are taking medication, this could prevent composting and also be harmful to the soil


How does a composting toilet separate urine from feces? ›

Most composting toilets will have urine going directly into the waste pile and the urine (along with moisture from solid waste) will be evaporated by an exhaust fan system that helps to reduce the overall amount of moisture in your composting toilet.

Do you ever have to empty a composting toilet? ›

Compost made from human waste loses much of its bulk so you will only need to empty the tray every couple of months depending on the usage of the toilet.

What are the drawbacks of a composting toilet? ›

Disadvantages of a compost toilet include more maintenance than standard toilets. Improperly or poorly maintained systems can lead to odors, insects, and health hazards. These toilets usually require some type of power source, and the end product must also be removed.

What happens if you have diarrhea in a composting toilet? ›

Because Diarrhea typically has a little more liquid in it than normal 'poop' you may find you might need to run the exhaust fan a little more than you would normally to help evaporate the additional liquid. Other than that, your composting toilet should function as normal, without any issues.

Does toilet paper go in composting toilet? ›

Any type of toilet paper is acceptable; less substantial brands (such as marine or RV paper) will compost the quickest. Diapers, wipes and tampons should not be placed in the solids bin.

How often do you clean a composting toilet? ›

In saying that, for the sake of throwing out a number, on average you can expect to empty your composting toilet every three months or so.

What do you do with the contents of a composting toilet? ›

What to do with the waste from a composting toilet
  1. Add it to an existing compost pile.
  2. Spread it around fruit or nut trees.
  3. Spread it over lawns.
  4. Spread it around non-edible gardens.
May 20, 2021

Can you put flushable wipes in a composting toilet? ›

Many people ask “can you flush biodegradable wipes?” The simple answer is – no. You shouldn't flush any wipes! It's good to , but even >non-plastic wipes should either be binned or composted. Biodegradable wipes made with organic cotton, viscose or bamboo simply don't have enough time to break down.

What maintenance is required for a composting toilet? ›

A properly constructed and operated composting toilet will require little or no maintenance. However, you should inspect it once each month for possible damage due to weather or other causes. Inspect the rear wall covers to be certain they are tightly sealed. If necessary, reseal them with tar or other material.

Do composting toilets smell outside? ›

If you're outside your outhouse, cabin, house or shed where your composting toilet is installed and you can tell there's a distinct smell around the area of the exhaust fan, this is pretty normal as all smells from the composting toilet are pushed up through the exhaust outlet by the exhaust fan and this lets smells ...

Can you pee and poop at the same time in a composting toilet? ›

You start each cycle by filling the drum with 1 gallon of damp and loose compost material, coconut coir is popular. Then you pee and poop as you do. No need to cover it with saw dust, dry leaves, or ash afterwards, you just spin it once after every use.

How do I keep maggots out of my compost toilet? ›

Like I said, you don't have to get rid of these maggots. In fact, some gardeners love having them in their compost because they break down food waste so quickly.
But if you want to combat maggots, you can:
  1. add about 1 cup of lime per 25 cu ft. of compost, or.
  2. add pine needles to your compost, or.
  3. add citrus fruit waste.
Jan 12, 2023

Can you put coffee grounds in a composting toilet? ›

1. Add coffee grinds. Your composting toilet shouldn't smell, but you could actually make it smell nice, by adding coffee grinds to it. Arrange to get coffee grinds from your local coffee shop on a regular basis, and add them to your toilet in whatever quantity smells good to you.

Can you put tampons in a composting toilet? ›

Yes, if you're using 100% cotton tampons, these can biodegrade in septic tanks or composting toilets. No, if you're using conventional tampons, usually made with plastic overwraps that interfere with the tampons breaking up and biodegrading.

Do composting toilets need electricity? ›

Given that composting toilets require electricity, there are some great environmentally friendly ways to go about generating this.

How long does it take to compost human poop? ›

Hot composting

The entire process can take about 20 days and is the sure way to kill all pathogens and eggs present in fecal matter. It is the best way to ensure human waste is composted properly and can be used on edible fruits and food crops as the matter undergoes high temperatures of about 65°C.

Can you put baby wipes in a composting toilet? ›

What you don't want to be putting down there is anything that won't biodegrade like nappies, wet wipes, plastic pad liners, etc. Note: Some medications can be toxic to your compost pile as they aren't absorbed or metabolised completely by the body.

Can you use worms in a composting toilet? ›

Composting worms are often used to speed up the decomposition process dramatically and reduce odors. Here at Uncle Jim's Worm Farm, we often receive orders for Red Composting Worms that go into composting toilets. These red worms are champion composting worms that we have cultivated over the past 25+ years.

Are composting toilets high maintenance? ›

Perhaps the biggest disadvantage of composting toilets is the increased level of maintenance and manual upkeep required. Slacking in your maintenance routine can lead to not only terrible odors but horrible messes and health hazards.


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