What is a Composting Toilet? The Dirty Truth About How They Work

Georgette Kilgore headshot, wearing 8 Billion Trees shirt with forest in the background.Written by Georgette Kilgore

Eco-Friendly Natural Products | December 12, 2023

Man with his hands on his hips looks at an outhouse structure and wonders what is a composting toilet and how does a composting toilet work?

Have you ever wondered, what is a composting toilet?

These eco-friendly versions of conventional water-hogging toilets are gaining more traction for homes and RV owners. But, before you make the switch, knowing the dirty truth about how they work is crucial before you buy.

In fact, you might be surprised about how they work… this guide examines the operation of a composting toilet and the best places for their use.

How Does a Composting Toilet Work? How Do Composting Toilets Work?

A composting toilet system collects human waste and converts it to compost or nutrient-rich matter.

You can power it using batteries or electricity, and its upside is that it uses little or sometimes no water and doesn’t emit a foul smell if you install and use it correctly.

It combines waste with materials like sawdust and leaves, and you can dump the mixture in your compost heap and leave everything else to the heat. These toilets come in various designs and run on different power sources for heating or ventilation, and you need to regularly empty and clean them.

How Do You Empty a Composting Toilet: Guidelines To Follow

If you search online for what is a composting toilet, various models will come up, so how you empty it generally depends on their design.3

For instance, home, RV, and caravan systems feature bio bags inside that you take out and dispose of in a waste facility or bin.

On the other hand, if you have one with batch processing, you only have to open the top, remove the seat, take out the container and replace it with another one. You will find a tray at the bottom for continuous cycle processing toilets that you pull out and empty.


Photo of a composting toilet made of wood.

(Image: Rene Cortin7)

Different manufacturers create their products to work differently, and before buying one, it helps to confirm the specific instructions first.

However, regardless of the type, remember to use a dust mask, wear gloves when emptying it, and wash your hands afterward.

Composting Toilet System Types

  • Self-contained systems- here, the various compartments are a single unit where the toilet and the compost tank are one, and they work for confined spaces like tiny houses and RVs.
  • Centralized systems- these composting toilets look like conventional versions but have a storage chamber below them or in the basement. Since they have more space, they also hold waste longer than the self-contained versions.
  • Single and multi-chamber toilets- the two main versions above further divide into single-chamber types that use aerators to evaporate the liquids and multi-chamber versions that separate liquid and solid wastes.

How To Use a Composting Toilet for Beginners

Composting toilets work almost the same as conventional versions, but there is no flushing, and you must empty the chambers. To use a composting toilet, line the inside with materials like coconut fiber or other carbon matter, which help maintain the carbon-nitrogen balance.

For simpler versions, you can use sawdust after each use; the liquids will drain into removable chambers while solids go to compost.

Depending on the model, you will need to stir the compost or cover it up with another sawdust layer.

What Is a Composting Toilet for House?

Composting toilets for the house resemble conventional types and are specially built for more storage since more people may use them.

They are often multi-chambered and centralized systems to avoid regular emptying.

Composting toilets for recreational vehicles are smaller in contrast and are often single-chambered and self-contained, allowing you to remove the container for emptying.

Features To Look Out for in the Best Composting Toilet

Here are some of the features to look out for in a composting toilet.


The system’s size is essential since you pick one that fits your space. Some can be larger than traditional types featuring ventilation fans or tanks to accommodate more waste, but they won’t be ideal if you have limited installation space.


Another consideration is how many people will use the unit because you don’t want a system that needs daily emptying.5 While you can go for a smaller and simpler type if you are the sole user, you will need a bigger, more advanced version for a family-friendly alternative.


Some versions use electricity/ solar power and water supply to run the ventilation fans and other processes. Others also feature water storage tanks or a steady water supply to remove the waste, but some are self-contained for off-the-grid use.

NSF Certification

One more factor you cannot ignore is the NSF certification, which indicates whether the product meets the basic standards of being odor-free and safe for use.

What To Do With Urine From Compost Toilet?

Urine is an excellent addition to your compost pile because it is rich in the compound.

You can supplement it with more dry leaves and sawdust to facilitate the decomposition process and create an effective heap with carbon and nitrogen content.

Are Composting Toilets Safe To Use?

If you don’t know what is a composting toilet and are worried that it may be unsafe or unhygienic to use, you can rest easy.

Like traditional toilets, these alternatives are safe and odorless, especially when you install and use them correctly.

Photo of a comfort room in the woods using a composting toilet.

(Image: 22114388)

It is crucial to set them properly and empty when necessary using the proper tools and following the guidelines. Y

ou can also confirm the best and safest usage from the product’s manual.

How Does a Composting Toilet Work in a Tiny House?

A composting toilet is brilliant if you live in a tiny or moving house. It is portable, safe for the environment, and doesn’t need an elaborate plumbing system.

Therefore, you can use it off-grid and wherever you want, and the best part is that it doesn’t occupy a lot of space, which is perfect for your tiny house.

How Does a Composting Toilet Work in a Van?

If you love seeing the country on wheels and spend most of your time on the road, a composting toilet will be very convenient.

It is waterless, doesn’t need plumbing, and effortlessly separates urine and solid in different chambers where you can bury the content in bio bags and empty the urine in toilets or sewers along the way.

Composting Toilet Pros and Cons To Note

Here are the common pros and cons of composting toilets:


  • It reduces your house’s water usage by 60 percent and saves you a lot of money
  • It is a cleaner and cheaper alternative than using septic tanks
  • It encourages composting and helps keep the soil more fertile
  • It doesn’t need a drainage system, making it perfect for tiny houses, outdoor cabins, caravans, and RVs
  • It is a cheap one-time purchase unit; you don’t have to hire an expert to install it


  • You must remove the waste manually (more toilet interaction than conventional types)
  • You need a more extensive system if more people will be using it
  • Advanced versions run on electricity, which generate some emissions.
  • Not installing it correctly is unsafe and can emit noxious gases and stench

What Are the Disadvantages of Composting Toilets?

The main inconvenience of using composting toilets is that they need a lot of maintenance due to the manual emptying and cleaning of the removable chamber. Otherwise, awful odors will ensue, and the unit will be a health hazard.

Some systems also need a connection to power sources, and you must monitor the air circulation, moisture, and other vital levels.

Additionally, some units are too small for family use, and you will need a more extensive (sometimes not aesthetically pleasing) system for your family’s needs.

What Are the Costs of a Domestic Composting Toilet?

Purchasing a composting toilet will cost between $50 for a DIY and $1400 for a self-contained version.1 In contrast, installing a septic tank will cost more than 75% of a regular composting toilet.

Manufacturers design their systems with fans and more elaborate features, hence the high price, but this is significantly lower than getting a septic tank.

Alternatively, creatives can make simple and cheap DIY versions that require basic materials.

Domestic Composting Toilets for Cabins: Best Composting Toilet for Cabin

You will find the composting toilet handy if you own a cabin in the woods and often escape to it when you need a quiet and calm place to relax. The best one should be compact, inexpensive, and accommodate the number of people using it.

Most go for single or multi-chambered versions depending on whether they have electricity access or want one for off-grid purposes.

You can choose one that fits perfectly with your cabin, but the upside is that you don’t have to deal with septic issues if the structure is in a rural area.

Where To Find Composting Toilets for Sale?

Composting toilets are available in various online retail stores like Amazon, and you can find one on eBay or any other eco-friendly shop near you.

The key is to carefully check the reviews and thoroughly research the product to see whether it will suit you.

Features of Luxury Composting Toilet

Self-contained composting toilets are the best options if you are going for luxury alternatives. They are often expensive since they are more convenient and boast more improved features, unlike the simple types.

Some have stainless steel components and in-built ventilating fans to make them easier to use and odorless. They also tend to have a higher capacity, allowing up to 90 uses before requiring emptying.

What Is the Best Composting Toilet for Tiny House?

There are some crucial factors to consider when shopping for a waterless toilet for your tiny home. Most importantly, you need one that fits inside its designated space, and you should always check the dimensions when shopping online and compare them to the size of the area.

Some are massive, given their additional features and other intricacies, but you can go for a smaller design if you have limited room.

Features of the Best Composting Toilet for Off-Grid

You should know what is a composting toilet if you live off-grid, love using eco-friendly natural products, and want an effective solution to your alternative lifestyle.

Before you buy one, some considerations will guide your choice for instance, will it be for long or short-term use?

The ideal option should work either way and be convenient for use. The disposal method is also worth considering, and you should know whether you need it for manure or you will dispose of it differently.

What Is the Best Composting Toilet for House?

When looking for a composting toilet for your house’s needs, you don’t mind the bulky designs with special incorporated features since you don’t have to move around with it, unlike caravans.

You can also consider how many people will be using it every day because you need one that doesn’t require emptying daily, which is inconvenient.

Educating the entire family on the best way to use it to keep it safe is also crucial.

What Is a Composting Toilet for RV?

Composting toilets for RVs are handy when you constantly move and need a convenient green bathroom and prevents the use of chemicals.

Unlike the standard types, where you must flush with water, the composting toilet for your vehicle doesn’t need plumbing or any water which is the ultimate way to handle waste organically.

How Does a Composting Toilet Work in an RV?

Using a composting toilet on your RV separates the liquids and solids into two compartments.

The solid-matter chamber contains organic carbon materials like peat moss or coconut fibers, and the user turns the crank on the side to mix them.

Various composting toilets come in different designs, but each has a separation system that facilitates waste decomposition.6 Also note that while liquids need frequent emptying, you can dispose of solid waste on schedules.

Composting Toilet for RV: Pros and Cons

If you want to install a composting toilet in your RV, you will appreciate how it is cheap, waterless, convenient, and green. It also doesn’t need expert installation or drainage, unlike the standard flushable toilets that use septic tanks.

On the downside, usage and maintenance may be tasking because it needs manual disposal methods, and you must consider how best to dump the waste.

RV Composting Toilet vs Black Tank: Which Is Better?

If you are looking for an eco-friendly toilet that spares you the cost of setting up the plumbing on your RV, the composting toilet is the ideal option. It is clean, saves money on sewage systems, and is portable.

On the other hand, the black tank is an intricate storage for flushed waste and is expensive to install.

Still, the upside is that you don’t need to manually empty the container, making it convenient if you want to avoid the hassle.

RV Compost Toilet Review: What Do People Say About It?

Depending on the model, customers have various opinions on composting toilets. If you are looking for the perfect one for your RV, you should check for reviews like easy installation, low maintenance, high capacity, lightweight, durability, fan installed, and non-electric.

Some types will also have negative reviews stating that they are pricey, heavy, tiny, need frequent emptying, and the liquid seeps into the solid compartment.

These reviews will guide you when making your final selection but note that each toilet has its pros and cons.

Cassette Toilet vs Composting Toilet: What Is the Difference?

Being on the road is thrilling, and you can install your private toilet in your caravan to avoid sharing public ones, and there are two main versions, cassette and composting toilets. The cassette uses chemicals to break down all the waste into a single tank that you empty into a dumping point.

However, a composting toilet features two tanks to hold liquids and solids, after which the solids compost with the carbon materials inside, and the urine separates into another tank that you empty more frequently.

Features of the Smallest Composting Toilet for RV

Many buyers are skeptical about buying bulky composting toilets that are often not aesthetically appealing and opt for smaller, sleeker designs for their RVs. The goal is to minimize space and look great inside the vehicle, which is impossible with massive toilets.

While larger toilets are okay for houses, tiny ones are better for caravans or homes on wheels. Manufacturers are shrinking their designs to target such consumers, ensuring no compromise on excellent capabilities like ventilation systems.

What Is the Best Composting Toilet for Van Life?

If you are all about van life and need a convenient way to relieve yourself without worrying about water plumbing, odor, complicated installation, or expensive systems, composting toilets are your best bet.

However, a first-time buyer has critical factors to consider before selecting one. First, pick one that is easy to maintain since you will mostly be on the road and second, go for a sleek, lightweight, sturdy design that you will use for a long time.

Myth Busting of Outdoor Compost Toilet

Below are some myths about composting toilets that are not true.

  • Composting toilets are as smelly as pit latrines. This is false because compost toilets use decomposing systems to stay odor-free when used and maintains correctly.
  • Models that use batteries are not as effective as electric versions. This is false since each system is a high-performance design regardless of its power .2
  • The resulting compost is unusable- false. This humanure is ideal for fertilizer for landscaping (flowers and shrubs).
  • They need unique toilet paper. This is also false since you can use any brand you want.

What Is an Airhead Composting Toilet?

The Air Head composting toilet is a compact, easy-to-use waterless system that stands out from other similar designs. It has a 12-volt ventilation system that dries waste and a urine separation system.

Odors disappear immediately, ensuring that it is comfortable to use, and the standard design looks like a conventional flushable toilet, giving you a sense of familiarity and peace of mind.

Can You Use Bamboo Toilet Paper With a Composting Toilet?

The composting toilet doesn’t limit the user on the toilet paper type. All variations work the same, including the eco-friendly bamboo toilet paper that many users prefer.

You assume it is like the standard toilet that is not restrictive since any toilet paper will go through the drainage system.

DIY Composting Toilet Plans and Materials You Need

You can quickly search online for various unique DIY composting toilet plans, but you will need some tools and materials.

You should find a 12 mm plywood, screws, wood glue, a 5-gallon bucket, a toilet seat, an electric drill, drill bits, a screwdriver, sandpaper, a handheld jigsaw, a pocket hole jig, and a woodworking file.4

What Is a Composting Toilet DIY? DIY Composting Toilet 5-Gallon Bucket

After selecting an excellent DIY composting toilet plan online, the next step is to gather your tools and get to work. It only takes a few steps to create a simple version using plywood and a 5-gallon bucket.

First, you build the toilet’s box and make it as comfortable as possible, like a standard toilet. You will need to consider the height and ensure that it is easily accessible and effortless.

The next step is to cut the hole through the center where the waste will fall inside, and you can customize the size.

Also, remember to use the file to soften the edges and touch it up with sandpaper.

Why Build a DIY Composting Toilet Kit?

There are several reasons why a DIY compost toilet is the best option for your home, caravan, or cottage.

  1. It is cheaper to set up than asking professionals to install septic tanks and sewage systems.
  2. A compost toilet is one of the eco-friendliest waste disposal options.
  3. A DIY compost toilet helps you save a lot of water.
  4. It is easy to install since you don’t have to worry about plumbing.
  5. Unlike other toilets, the composting system is odorless thanks to aerobic decomposition using carbon materials.

Composting Toilet Diarrhea: Can You Use a Composting Toilet in Case of Diarrhea?

While you can poop in the composting toilet, the case is slightly different in matters of diarrhea. Since the content is runnier or has more water than regular waste, you will have to run the fan more to help evaporate the liquid and eliminate the odor but still, your toilet should work regardless of diarrhea.

What Are Compostable Trash Bags?

Unlike petroleum-based bags, bio bags or compostable trash bags are the best for the environment because they quickly break down. No more landfills are full of plastic bags that take decades to decompose and release GHGs into the atmosphere.

Standard toilets use more than 5 gallons of water per flush, meaning energy and money are wasted daily, which translates to a larger carbon footprint. Luckily, composting toilets are here to help.

They use almost no water and take advantage of natural chemical breakdown processes to convert waste into humanure that you can reuse in your home.

Composting toilets come in different designs at various costs, and you can create a cheap DIY version using local materials. You can search what is a composting toilet online for more details and DIY plans and engage your entire family in an eco-friendly waste management method.

Frequently Asked Questions About What Is a Composting Toilet

What Is a Split System Composting Toilet?

From the name, the split system composting system is in two sections, the pedestal, which is the top part, and the tank, which stays underneath. It is one of the largest types in the market and is ideal for homes and cottages.

What Is a Composting Toilet System for Home?

Composting toilets are better for the environment and don’t use as much water because the waste mixes with carbon materials and decomposes to form humanure which you can use as fertilizer for your landscaping plants. Home systems are often bulkier to accommodate more uses to avoid frequent dumping.

What Is a Dry Toilet in a Camper?

A dry toilet for your rig is a relief option that doesn’t need chemicals or water to flush. It borders between a wastewater and a composting option and is portable; the best part is that your camper doesn’t need a sewage system.

Can You Poop in a Composting Toilet?

You can poop inside a composting toilet, which is the point behind its design. The goal is to convert the solid waste into humanure or fertilizer through bacterial breakdown to eliminate the smell and the need for flushing with water.

Can You Pee in a Composting Toilet?

You can pee in a composting toilet since it has absorbing materials like sawdust that helps eliminate the odor. Systems also have urine separation chambers, but you must dispose of them more frequently while maintaining the toilet.

What Is a DIY Composting Toilet?

You can buy a complete composting toilet from retailers all over the country, but a DIY version is cheaper and easier to customize. You only need a few materials and tools to make one with a 5-gallon bucket capacity.

How Do You Install a DIY Composting Toilet Urine Separator?

You can screw a urine separator beneath the plywood lid at the top. It helps channel the liquid in a separate container away from solid waste to avoid the foul smell that emanates from the two mixings.

How Do You Make a DIY Composting Toilet With Fan?

It can be tasking to install an intricate fan inside a composting toilet; only ready-made versions use it and need the power to run them.

However, some devices ways use small computer fans, but for such a simple bucket toilet, you will have to use the most absorbent materials to eliminate the odor and keep the waste as dry as possible.

How Do You Make a DIY Composting Toilet No Smell?

The best way to avoid the foul smell of DIY composting toilets is to use enough absorbent materials like peat moss, dry leaves, sawdust, and coconut fibers. You can also install a small fan inside for proper ventilation.

How Does a Composting Toilet System for RV Work?

Like any other composting toilet, unique models for RVs have a solid-liquid separation system to eliminate odor and keep the system safe for use. However, the best designs for RVs tend to be smaller and sleeker for aesthetics and to minimize the use of space in the vehicle.


1American Home Shield. (2022). To Flush Or Not To Flush: The Truth About Composting Toilets. American Home Shield. Retrieved November 8, 2022, from <https://www.ahs.com/home-matters/cost-savers/the-truth-about-compost-toilets/>

2Cabin Life. (2022). Environmentally Friendly Toilets. Cabin Life. Retrieved November 8, 2022, from <https://www.cabinlife.com/articles/environmentally-friendly-toilets>

3Ecoflo. (2018, January 10). How To Empty A Composting Toilet – The Complete Guide. Ecoflo. Retrieved November 8, 2022, from <https://ecoflo.com.au/blog/how-to-empty-a-composting-toilet-the-complete-guide>

4Gemes, N. (2020, September 29). Build Your Own DIY Composting Toilet Cheaply and Easily. Green Citizen. Retrieved November 8, 2022, from <https://greencitizen.com/blog/diy-composting-toilet/#t-1595170314237>

5SanSone, A. (2022, October 24). The 5 Best Composting Toilets of 2022. Treehugger. Retrieved November 8, 2022, from <https://www.treehugger.com/best-composting-toilets-5078179>

6The RV Geeks. (2022, July 28). How Does a Composting RV Toilet Work? The RV Geeks. Retrieved November 8, 2022, from <https://www.thervgeeks.com/how-does-a-composting-rv-toilet-work/#are-there-different-types-of-composting-toilets>

7Composting toilet Photo by Rene Cortin / CC BY-SA 4.0 DEED. Resized and Changed Format. From Wikimedia Commons <https://commons.wikimedia.org/wiki/File:Composting_toilet.jpg>

82211438. Pixabay. Retrieved from <https://pixabay.com/images/id-1376429/>