The ultimate guide to composting toilets: What is a dry composting toilet and how does it actually work?

The ultimate guide to composting toilets: What is a dry composting toilet and how does it actually work?
Table of Contents

Wherever it is not possible to connect a conventional toilet, composting toilets are a modern, sustainable and mobile alternative. The name says it all: the toilet works without water, the waste is separated by a special insert and fed into two separate containers. The urine flows into a canister, while the large business ends up in a bin lined with a bin liner. The composting toilet does not use chemical additives. Instead, the use of litter ensures that no unpleasant odours develop.

Why is it worth using a composting toilet?

A composting toilet offers a number of advantages. First of all, it does not require water, which means that it does not need to be connected to either the water supply or the sewage system. This makes it a more environmentally friendly option that helps to reduce water consumption and reduces the load on sewers. In addition, composting toilets are very easy to install and clean as they do not require complex technology.

Another advantage of composting toilets is their versatility. They can be used as a mobile toilet on the road as well as permanently installed. This makes them suitable as a sanitation solution in areas without infrastructure.

The advantages of a composting toilet at a glance

Environmentally friendly                                                       

Dry composting toilets do not use chemical additives and instead rely on sustainable litter materials. This makes them a contemporary alternative to the conventional camping toilet.


Since a dry composting toilet does not require water, you save valuable resources on the road. In addition, you are well advised to use a composting toilet wherever water is a scarce resource.

Autarkic and mobile                                                       

Composting toilets do not require a connection to the sewage system. This gives you the freedom to enjoy the comfort of your own toilet wherever the installation of a conventional toilet is not possible. In addition, their compact dimensions make them very easy to transport and therefore mobile. By the way, with a composting toilet you can leave the waste disposal stations to the left. You no longer need them. 😉


By using litter, not only are poop smells avoided, but with a composting toilet you will never again have to smell the typical chemical smell when emptying and cleaning. Why exactly fresh urine is odorless and why the big business in a separation toilet remains odorless, you can find out here

Easy to handle                                                                          

Keep it simple, keep it convenient. Composting toilets are reduced to the essentials and are therefore child's play to use and clean. Without unnecessary frills but still with the comfort of your own private toilet, you can experience the feeling of pooping at home everywhere.

    What materials does a composting toilet consist of?

    Composting toilets are usually made from a variety of materials, such as plastic, stainless steel or wood. Each material has its own advantages and disadvantages.

    Plastic is a very popular and often used material for composting toilets because it is light, very easy to clean and therefore absolutely hygienic. One disadvantage is that it can become brittle over time.

    Stainless steel is more resistant than plastic and offers a longer service life. However, it is also more expensive and heavier, which can make transport and installation more difficult. Especially when every gram of weight matters in the van, stainless steel can be a showstopper.

    Wood is also a very popular material for composting toilets. It is natural and aesthetically pleasing. The downside is that as a natural material, it is more susceptible to moisture and mould and requires more maintenance. So it makes sense to oil or glaze toilets made of untreated wood every now and then to protect them from moisture. Similar to stainless steel, wood is also much heavier than plastic.

    The choice of material for a composting toilet depends on individual needs and preferences. It is important that the material is robust enough to withstand the demands and at the same time comfortable and easy to clean. Last but not least, the location also plays a role: If your toilet is placed in a shower and will therefore be in permanent contact with water, you will not enjoy a wooden toilet in the long run, as the material - even if it is glued very well - will swell up at some point.

    How a composting toilet works

    Interior of a Composting Toilet

    Externally, a composting toilet consists of a body, a toilet seat and a lid that closes the toilet. The interior is made up of three main components: the separation insert, the urine canister and the solids container. The insert is usually made of plastic or stainless steel and is inserted into the toilet tank or is permanently integrated into the toilet seat.

    With its lowered shape and its two openings, the separation insert ensures that the solids and the liquids are collected separately. Through the simple principle of gravity, solid waste falls into the designated container, while urine runs into the canister. This prevents the big and small business from being mixed together, which can lead to unpleasant odours.

    To avoid this, cover the big business with litter at the end of the session. The litter promotes the drying process and also binds odours. The whole thing works according to the "dog poop principle": a fresh dog poop has the unpleasant property of smelling seven miles into the wind. Once it has dried, however, you can "safely" sniff the sole of your shoe without an unappetising odour wafting towards you.

    Use of a composting toilet

    Dog using Composting Toilet

    Using a composting toilet is child's play: Lift the lid, take a seat and let it run in a relaxed manner. To make emptying the container as easy as possible, line the solids container with a bin liner. Before the first session, put a cup of litter in the bag. As with a conventional toilet, you simply throw the toilet paper into the solids container.

    At the end of your session, sprinkle your solid waste with two more cups of litter to speed up the drying process. When the solid waste bin is full, remove the bin liner, tie it tightly and dispose of it in the residual waste. It is also possible to compost the solids under certain conditions.

    You can empty the urine canister in any toilet that is connected to the sewage system, regardless of whether it is at a campsite, a rest stop or a car park with a toilet. If you have a spare canister with you, you can take the liquid gold home with you and empty it in the toilet at home if your journey is not too long. Diluted, you can also use your little business as fertiliser. This variant is particularly interesting for all those who have a garden or allotment plot with the appropriate plants.

    Because of its simple functionality, there are only a few things you should keep in mind when using your separation toilet. Here you can find out what the 5 biggest pitfalls are and how to avoid them.

    Solids removal

    The easiest way to dispose of the solids is in the residual waste. Dog poop bags or nappies are also disposed of in household waste. In other countries, the regulations may vary. Be sure to adhere to local regulations and best practices when disposing of your waste. 

    Solids composting

    Solid composting

    By composting human feces you produce valuable fertilizers for horticulture. To ensure safe and hygienic composting, there are a few things you should keep in mind.

    Collect the feces separately from other waste. This way you avoid contamination with harmful substances. Use untreated, unbleached, environmentally friendly paper that is suitable for composting. Alternatively, you can collect the paper separately.

    Important: Compost only the feces of healthy people without contagious diseases. This minimizes the risk of transmitting pathogens. You should also refrain from composting if you take medication that is stored in the excrement. Otherwise, antibiotics and the like will end up in your carrots when you fertilize them.

    You can find out what composting options are available and how exactly you can turn your large stores into valuable humus in our article on composting human feces.

    Urine as fertiliser

    Diluted with water, urine becomes a high-quality natural fertilizer. With ingredients such as nitrogen, phosphorus or potassium, the liquid gold promotes the growth, flowering and fruiting of many plants.

    Find out which plants react particularly well to urine fertilization, what you should bear in mind and for which plants it is better to use an alternative fertilizer in our major article about "the liquid gold from the dry composting toilet".

    What accessories do you need?

    Which toilet paper is suitable?

    Truck and a Composting Toilet

    There are different types of toilet paper, which differ in their composition and degradation behaviour. Which one is best suited for your composting toilet depends on how you dispose of it. If the big deals end up in the residual waste bin, you are basically free to choose your paper.

    Conventional toilet paper is made from cellulose and decomposes most slowly compared to other types of toilet paper. However, it can be used in composting toilets without any problems if you dispose of the solid waste bin regularly.

    There is also special toilet paper that is optimised for composting toilets. This toilet paper is usually made of recycled paper or bamboo fibres and disintegrates faster than conventional toilet paper. We only sell recycled toilet paper that is free of chlorine, dyes and fragrances.

    For environmentally friendly disposal, it is important that the toilet paper you use is not treated with chemicals or synthetic materials that can slow down degradation or leave harmful residues. Therefore, for the sake of the environment, you should avoid toilet paper that has been treated with fragrances, bleach or other chemicals. This is a must for the composting option. Otherwise, dyes and bleaches will find their way into your manure.

    Which litter should I use?

    Litter and Composting Toilet

    You need litter to use your composting toilet. You spread this on the excrements after going to the toilet. To ensure that your business can dry well, it is important to use materials that absorb moisture well and also bind odours.

    Small animal litter, organic cat litter, special mixtures with activated charcoal, fine bark mulch, sawdust, Terra Preta, coconut bricks or even dried coffee grounds are particularly suitable. You can read about the advantages of the different types of litter in our article "Which litter for separation toilets should I use?".

    We advise you not to use granulated cat litter. On the one hand, it is often chemically pre-treated and therefore tends to smell, and on the other hand, the granulate easily forms lumps that become heavy and can cause the bag to tear.

    How do remedies with activated charcoal work?

    Activated carbon is a very effective agent for odour binding and is therefore used in various products, such as filters for air purifiers, odour removers for the refrigerator or even in special litter for composting toilets.

    The mode of action of activated carbon is based on its porous structure. The high number of pores and channels in the carbon creates a very large surface area that can be used to absorb odour molecules. As soon as the odour molecules come into contact with the activated carbon, they are bound in the pores of the carbon and thus neutralised.

    Activated charcoal also has the ability to absorb moisture, which helps to reduce unpleasant odours. By absorbing moisture, it inhibits the growth of bacteria and mould, which are often responsible for bad odours. Litter with activated charcoal is therefore very suitable pure for littering your big shops or mixed in with the litter of your choice also as an additional odour blocker.

    Do I have to use special bin liners?

    Trelino bin liner

    Similar to toilet paper, the same applies to trash bags: You are free in your choice. Since the composting toilet is an environmentally friendly product, plastic bags do not really fit the principle - but they can of course be used.

    In our article about the bag for the poop, you can find out what types of garbage bags are available, how recycled bags differ from compostable or organic bags, and how to find the bag that suits you best.

    Two quick tips
    Compostable bags do what they were designed to do after a while: they decompose. To avoid unpleasant "Ratchet! and Oops!" experiences, we recommend lining your solids container with a "safety bag." A good option for this is tear-resistant trash bags made from recycled materials or reusable polypropylene.

    If you decide to compost, it makes sense to do without bags altogether and put the waste directly in the composter or on the compost heap.

    Places of use

    White Camping Van and a Trelino Composting Toilet

    Due to their independence from water supply, sewage system and disposal stations, composting toilets can be used in many different areas. The most common areas of application for composting toilets are camping and use on holiday trips.

    Especially on small campsites where there are no sanitary facilities, composting toilets can be ideally used to enable self-sufficient camping. They can be used in all places where no running water is available or there are no disposal stations for black water. They are therefore ideal for allotments or other small garden sites.

    We have compiled a small overview of the possible uses and the greatest advantage for you.

    Off-roader, campervan, panel van Small, compact, self-sufficient: This is how you discover remote places without public sanitary facilities.
    Caravan, camper Easy disposal: You are finally independent of disposal stations.
    Car Space-saving miracle: Suitable as an emergency toilet or to take along for nature-related hobbies, fits in the boot or footwell of the car.
    Boat Easy handling, chemical-free: No cumbersome pumping, no environmental pollution.
    Garden House, Tiny House, Holiday Home  Usable without connection to the sewerage system: Easy installation, allows use with the comfort of a conventional toilet and a home-like feeling.

    Installation of a composting toilet

    Installation of a Composting Toilet

    In general, the installation of a composting toilet always depends on the choice of location. In a Tiny House, for example, you have enough space to install the toilet in the bathroom. If it's a fixed Tiny House and not a mobile one, you don't need to anchor the toilet firmly in the ground because your house doesn't move.

    In this case, a level floor is sufficient to set up and use the composting toilet. Of course, things are different in a campervan or motorhome. Here it is important that the composting toilet has a good, secure stand and is mounted in such a way that it does not sway or slide while driving.

    Many models can either be connected directly to the floor with the body or can be firmly integrated into the vehicle via a mounting plate. In a car or off-roader, the composting toilet should be positioned so that it is not thrown through the vehicle during emergency braking. The boot or footwell are good places for your toilet.

    Connection to the ventilation

    Fan Set

    Composting toilets can be connected to a fan or an existing ventilation system. With the help of a fan, the drying process is intensified. Small composting toilets are not suitable for connection because the body and the containers inside do not leave enough space for the exhaust air.

    If you use a 12-volt fan, a switch can be connected in between so that you can operate the fan when needed and it is not permanently in operation when the engine of your vehicle is running. Whether you need a fan depends on where your journey takes you.

    During longer stays in warmer climates, urine can cause moisture to collect in the body, disrupting the drying process of the solids and causing odours. In this case, the use of a fan is advisable. Or simply empty your containers more frequently. In any case, the proof of the pudding is in the eating. Our composting toilets can be easily retrofitted with a fan.


    Vinegar Sprayer

    Cleaning a composting toilet is as easy as using it. With time-honoured household remedies such as diluted lemon or acetic acid, the separation insert, solids container and urine canister can be cleaned hygienically and kept fresh. You can use the vinegar as well as the citric acid (at about 10% acidity) pure or diluted.

    PH-neutral cleaners or products with effective microorganisms are also very good for freshening up your composting toilet. Avoid aggressive cleaning agents such as power cleaners, chlorine-based agents and alkaline, acidic or solvent-based cleaners. These can damage the material of your composting toilet. The same applies to the use of scouring pads. These roughen the surface of your composting toilet and its containers and make them porous.

    Cleaning the separator insert

    A small spray bottle is suitable for applying the cleaning solution. Simply spray the solution onto the separator insert and then wipe with toilet paper or a soft cloth. You can then throw the toilet paper into the solids container.

    Cleaning the solids tank

    To prevent the plastic of the containers from taking on odours, we recommend regular cleaning with agents containing effective microorganisms or mild cleaning agents. If you do not use bags, it makes sense not to clean the solids container. Due to the excrements, there are already microorganisms in the solids container, which ensure that the composting process is accelerated.

    The longer the solids remain in the bin, the fewer odours will be produced because composting has already begun. If you still want to clean the container, simply use pure water or pH-neutral cleaners or agents with effective microorganisms.

    Cleaning the urine canister

    Rinse the urine canister regularly with diluted acetic acid or vinegar essence. On the one hand, this prevents the formation of urine scale and the associated odours, and on the other hand, it keeps your canister hygienically fresh.

    Attention! Never use pure water to clean your canister! The combination of residual urine droplets and water promotes the formation of urine scale. How you get rid of it, you can read here.

    Cleaning cycle

    After each use, you should spray your divider with diluted vinegar or citric acid and wipe it down. Cleaning is particularly recommended if a transaction has left its mark. The urine drain is also happy to be wiped down occasionally.

    Rinse the urine canister with diluted acetic acid after emptying. To do this, pour a little acid into the canister, screw on the lid and shake it vigorously. It is ready for the next use. If you find yourself without any acetic acid at hand, don't worry. Empty the canister, use it again and rinse it properly at the next opportunity.

    What is the secret of effective microorganisms?

    Cleaning agents with effective microorganisms are a natural and gentle alternative to conventional cleaning agents. They contain various natural organisms such as lactic acid bacteria, yeasts and photosynthetic bacteria, which together produce a variety of cleaning effects.

    Effective microorganisms are versatile. They can neutralize unpleasant odors, dissolve and break down grease and dirt, and rid surfaces of germs. By reducing harmful bacteria and fungi, these busy all-rounders support the natural ecosystem. In our article on the work and effect of effective microorganisms you can learn more about the little superheroes. 

    What happens during diarrhoea?

    In general, diarrhoea is not a problem when using a composting toilet. If the solid turns out to be more liquid, you simply use more litter to bind the moisture. If, on the other hand, there is only talk of liquid instead of solid, the only thing that can be done is to tie the bag shut and dispose of it.

    Tips for women

    Woman using Composting Toilet

    Admittedly: Men have it a bit easier on the composting toilet. Where they sit down and let themselves go, women have to slide back and forth slightly in order to specifically separate solid from liquid. 

    In addition to finding the right sitting position, many women also ask themselves, "What do I do when I have my period? Can I even use the composting toilet during this time?"

    The good news: Sure you can! What you should consider when using the composting toilet during your period and how to find the best sitting position for you, we tell you in our composting toilet ladies special.

    Important aspects when using a composting toilet

    Your separation toilet is a modest quiet place. It does not need more than litter to be happy. For cleaning, diluted acetic acid is enough for her, depending on the size and material you please her with a fan that boosts the drying process. Some things, however, she does not like at all. We reveal the top 5 no-gos in the drying room here.

    With the right use and care, however, a separating toilet is an absolutely hygienic, practical and simple solution for mobile business on the road or in any place where a conventional toilet can not be installed.

    In order to enjoy the environmentally friendly toilet for as long as possible, you should take the following tips to heart:

    • Always use a composting toilet while sitting down. Small transactions while standing or free-floating actions go in or on the pants!
    • Take a look into the urine canister in between to check if there is enough space left for the next session. Otherwise, the last drop can cause the canister to overflow.
    • Do not use wet toilet paper. This has a counterproductive effect on the drying process of your solids. An alternative is to use foam products that are applied to the toilet paper so that it can be used like wet paper.
    • Empty the urine canister regularly to prevent the formation of bacteria and odours.
    • Make sure that wooden toilets are well ventilated. Either use a fan or leave the lid open occasionally (e.g. overnight). As a natural product, wood reacts more sensitively to moisture and is more susceptible to the formation of mould.
    • Children can use a composting toilet without any problems. However, small children should be held by adults when going to the toilet so that they do not slip off or into the toilet.
    • Never use pure water to clean the urine canister! This can cause urine scale to form, which is difficult to remove from the canister and causes unpleasant odours.

    Is there a difference to the dry toilet?

    Yes, the main difference between composting toilets and dry toilets is that composting toilets separate the small and large business from each other, while dry toilets put the excreta together in one container. Dry toilets do not contain a separating insert.

    Since the dry toilet is the mother of all dry separation toilets, we have dedicated a separate article to it. Here you can find out how the dry toilet works, where it is still used today and what its strengths and weaknesses are. 

    What is the difference between a composting toilet and a chemical toilet?

    The dry composting toilet or simply composting toilet has established itself as an alternative to the chemical toilet. The chemical toilet consists of a container filled with a chemical solution. Alternatively, there are models that direct the chemical solution into the liquid-filled container at the push of a button.

    The solution contains enzymes that decompose the excrement. The lid of the container is equipped with a toilet or seat. After the business is done, the chemical solution is flushed through the hole in the toilet and mixed to decompose the excrement.

    Composting toilets, on the other hand, separate excreta mechanically without using chemicals. Chemical toilets contain highly effective chemical additives that have an antibacterial effect. However, these additives not only endanger people's health, but also the environment.

    Disposing of the excreta from a chemical toilet is more complicated. Due to the chemicals contained, the excrements may only be disposed of in accordance with strict regulations. When travelling, for example in a mobile home, this can be difficult if there is no disposal station nearby.

    Disposing of faeces and urine from the composting toilet, on the other hand, is very simple. You can either dispose of the urine via a conventional toilet or use it in diluted form as fertiliser in your garden. Thanks to the waste bags, you can easily dispose of solids in your household waste. This is also uncomplicated when travelling. It is best to find out about the legal regulations in advance.

    As the chemical toilet can still be found in many vehicles, we have taken a closer look under the lid of the classic camping toilet.

    In this article, you will find detailed information about how a chemical toilet works, how much water it uses and a large comparison table with the dry separation toilet.

    What are the advantages and disadvantages of composting toilets?

    Waterless, chemical-free, hygienic, environmentally friendly and easy to dispose of: composting toilets offer a number of advantages over conventional WCs. Connection to the local sewer system is not required. Dry toilets work without chemicals and still allow excreta to decompose naturally.

    Another advantage of dry toilets with a separation system is their environmentally friendly disposal. The excreta are placed directly in the normal household waste and can thus be disposed of easily. The separation system of dry toilets also minimises the odour of the excreta. It makes the composting toilet self-sufficient and independent of a sewer system.

    Accessories of a Composting Toilet

    One disadvantage of using a dry toilet with a separation system is that special accessories such as waste bags or litter are required. However, when using a conventional chemical toilet, you also need chemicals and water to use it.

    Outlook: Dry composting toilet quo vadis?

    Trelino Footbridge lake

    Composting toilets have not only arrived in the present, the future belongs to them. What a few years ago was dismissed as a new-fangled toilet gimmick in the camping sector is enjoying ever greater popularity. Yet the principle is old hat and has been established in Scandinavian cottages for a long time. In this country, more and more people are discovering for themselves and the environment the advantages and freedom that a composting toilet brings. The trend is increasingly moving towards the environmentally friendly and sustainable versions of the camping toilet.


    There are many different toilet systems. They all have their individual advantages and disadvantages. The composting toilet is good for the environment because it does not use any chemicals or water.

    Nevertheless, the system is very uncomplicated and hygienic. Before you decide on a particular system, you should compare the different options and adapt them to your needs. Up to now, dry toilets have been associated with prejudice. The smell is too strong and the cleaning too unhygienic. The dry toilet with separation system now offers a solution. Self-sufficient without chemicals, you can easily dispose of both solids and urine and use it anywhere.

    If you decide on the toilet with separation system, all that remains is to choose the right model. You can currently find numerous composting toilets in different sizes and made of different materials. In any case, you are choosing an environmentally friendly, simple and hygienic solution.


    • Giacomo Catalani

      E’ da un po’ di tempo che guardo con curiosità questo tipo di bagno ma ci sono alcune cose che mi spingono a non prenderlo in considerazione, la prima è il costo, trovo inappropriato che un tipo di WC così semplice nella sua costruzione possa costare addirittura il doppio del WC a cassetta tradizionale, costruzione molto più complessa, ovviamente, se ne deduce che buona parte del costo è squisitamente una questione di politica commerciale.
      La seconda è il fatto che avendo un van con la cassetta thetford dovrei modificare l’esistente con un modello non adatto alla trasformazione, certo se ci fosse un kit di modifica del wc a cassetta classico, cosa del tutto possibile, il discorso sarebbe diverso e magari lo potrei prendere in considerazione più facilmente.
      Trelino® Composting Toilets replied:
      Grazie per il tuo messaggio. Comprendiamo le tue preoccupazioni sul costo, ma vogliamo sottolineare che i nostri bagni sono prodotti eticamente in Germania con materiali di alta qualità. Apprezziamo il suggerimento di un possibile kit di modifica per il wc Thetford tradizionale. Grazie ancora per il tuo feedback.

    • Rubaud arlette

      Bonjour est ce que vos toilettes a séparation seraient adaptées pour un usage en refuge?
      Trelino® Composting Toilets replied:
      Oui, nos toilettes à séparation sont parfaitement adaptées pour un usage en refuge, car elles ne sont pas connectées au système d’égouts et ne nécessitent pas d’eau ou de produits chimiques.

    • Carsten

      wie kann ich in meinem Off Road Camper die Toilette in der Duschwanne befestigen. Kleben, Bohren, … fällt raus. Befestigen aber Pflicht, werde auch das SOG System nutzen wollen.
      Trelino® Composting Toilets replied:
      Hallo Carsten, du könntest Magnete oder Kunststoff Klettband verwenden. Diese Befestigungsvarianten können überall angebracht werden, je nach Gegebenheit. Zudem bleibt auch immer die Lösung mit Gurten. Ganz liebe Grüße Justyna – Team Trelino®

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