Boxio Toilet (and sink unit)


Advanced Member
Apr 1, 2018
Northern Virginia
The time came for an improvement in our toilet set up we use in and out of our Four Wheel Camper Hawk. This might be of interest to some:

Over the past few years our camping toilet has been a simple bucket toilet. This system works pretty well overall. It consists of a plastic 5 gallon bucket and a simple Reliance brand snap on toilet seat, the original bucket snap on lid and some plastic waste bags, absorbent such as kitty litter/sawdust or wood pellets, a pump bottle of hand sanitizer and some baby wipes. All the supplies fit in the bucket.

This Reliance toilet rig has been low cost, simple & easy to use and clean and works pretty well...up to a point. For a "quick one" or a day or two this system works. However, past this limited time frame the issue becomes the amount of urine deposited overwhelms the system. Thankfully we have an external storage area for the unit, and it is always stored outside and rarely used inside the camper. You can add chemicals to address the smell...but my impression is that you just replace one bad smell with another. On occasion the disposal of the waste bags has presented a problem where the location we were at had no waste disposal and/or it would not be appropriate or possible to bury the solid waste. Overall, this simple bucket system works very well as an emergency or overnight kit, but for long term use it falls short. The problems are odor issues, the combination of solid and liquid waste, and at times waste disposal. It is a system that some of my camping partner(s) are happy to have in "a crisis", but for any longer term use they essentially just "tolerate" it.

I want to improve this toilet situation to improve the camping experience for both me and other members of my family, expand the usefulness of the toilet for longer term use and address the issue of odor. Based on a recent experience of using a separated/composting type toilet I want to try an approach that offers separation of solid and liquid waste. I want a lightweight, simple, easy to clean/maintain toilet system that offers a urine diverter and has a simple and responsible waste removal/disposal system. I want a dry liquid chemicals or water flushing needed as at times this unit will be stored and used in freezing temperatures. The entire toilet rig must fit into my existing exterior storage cabinet and leave room for the other items I store there. The unit must be capable of withstanding and not leaking during the jolting/jarring/bouncing found on off pavement travel when the toilet is empty or partially filled.

I've started researching and there are some home-built systems that would allow me to continue to use my present system with the addition of a urine diverter. These diverters just clip on or are otherwise mounted to a standard plastic 5-gallon bucket. One issue with this approach is that the diameter of the bucket limits your available space for comfortable and effective "aiming" of the two bodily functions under discussion.

This informal research did however steer me more firmly toward the waste separating type of portable toilet. Many YouTube videos are available that give detailed reviews of these various toilets and the experiences and benefits/pitfalls of the type. These smaller portable units are more "waste separating" than true "composting" units. A typical user will be emptying the unit every few days...not really enough time for "composting".

Two offerings seemed to offer what I was looking for. Both are from companies sited in Germany. Both designs are essentially sturdy plastic boxes with well-designed waste separators with a toilet seat. The firms are Trelino and Boxio.

I was impressed with the simplicity and features of the Boxio. Boxio appears to be a fairly new company out of Germany. They offer a separating/composting toilet (and also a neat sink unit) that is based on a basic foundation that resembles a US type plastic milk crate. The toilet unit is very simple, practical and meets my specific weight/size requirements. It seems to offer the best features/cost combination.

I found and bought the toilet via Boxio direct, but it is also listed via Amazon. They also offer a sink unit that would be practical for some folks too. Here are some initial observations. Caveat: based on one day's field use and urine only.
The only real assembly required is the installation of 4 screws with the allen wrench supplied, and the threading and knotting of the cord for the "hinge". The components all fit together well, and the unit is as expected lightweight and of a size that balances good "size for use" and good "size for storage in a small camper". The flat black color is unobtrusive when stored under the rear area of my truck camper on the ground. Just as a note I weigh 220 pounds and the unit is sturdy enough in my opinion for long term use.

As this is a separating toilet under the toilet seat insert are two containers. The urine container comes with two screw on lids - one for use and one for carrying. The "in-use" lid has a rubber seal port that seals around the urine "tube". You can buy a plug for the urine tube from Boxio or it's likely Ace Hardware has a plug that would work. The "carry lid" is for the run of shame to a dumping location and is a full seal lid. Of note is that the solid waste container does come with a decent sealing lid. The lid can be stored in the toilet out of the way and used to seal off the solid waste part as needed. I'll likely be using the lid between solid material deposits to reduce odors.

I also got the additional base platform which raises the toilet seating area from about 11" to 15 3/4" and provides a storage area for various things like waste bags, compost media, hand sanitizer and toilet paper/baby wipes. For me at 5'10 the 11" toilet height is doable...but the addition of the base is appreciated for a bit of extra height. You could also just cut a couple of 4x4" sections of lumber if you wanted a boost. I carry several already for tire and jack blocking. The base comes with 6 plastic clips to join the base and the toilet together. It works, but for field use these clips are a bit of a bother, especially with cold fingers. The base and toilet fit together well, and I just may forgo the clips most of the time or come up with a different latching system.

Some resources:

Here is the US website for BOXIO:

A YouTube review of the BOXIO toilet and sink unit:

US website for the Trelino toilet offering:
Thanks for that great description of how you arrived at this particular solution.

I am a bit confused as to how this is a composting toilet, since the solid's container is only good for 8-10 uses. Two people, that's not even a week. And then you have to toss out the bag, which will clearly still be just mixed ingredients, not compost.

I do like the very compact size. It would fit where I have my bucket now. But with my bucket I use "Poo Powder" and it supposedly turns the contents of the bucket into landfill friendly solids. And they don't stink (too much). But it is still unpleasant to deal with.

So, I look forward to a more extensive usage report!
I also question if the name composting is appropriate for these toilets. Friends of ours bought a Trelino toilet and highly recommend it. So I ordered one and three weeks later they have not shipped it. Not impressed!
In order to properly "compost" you must have air circulation and the contents must be agitated. The design looks comfortable to use, but I think the smell may become funky with multiple uses.

We have been very pleased with our set up here:

This unit folds down to just a few inches and stows nicely in the camper. We store the waste bags outside in a bucket with a GAMMA lid attached to the bumper with a custom mount. The shower stall is great for privacy when needed.

We mostly pee outside, but the WAG bags do absorb quite a lot if need be. In the camper at night or when it is too cold to go outside we each have a container for our pee that we dump in the morning. The pee containers are great as we don't need to find a place to pee when driving. Just pull over and kneel down in the camper.

We do use a Natures Head composting toilet in our off grid cabin and it is awesome!

Please keep us updated of how your new system preforms for your needs.


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Prior to purchasing a Trelino EVO M separating toilet, I used a Reliant style lid for 5 gallon paint bucket and pine pellet litter in the lined bag. The Trelino is pricey, about $400, when on sale - but I like the urine separator.

The solid waste compartment at the rear of the toilet is rather small and requires a plastic bag liner, along with some type litter. Clean up requires a vinegar and water solution in spray bottle. What I like about the separator design is the solid waste bag doesn't have any liquids that can leak. It may be me, but I still feel guilty disposing the bag into a dumpster.

The urine tank is in the front and makes for a quick middle of the night toilet run. If two people are using it, definitely empty the urine tank each morning.
Vic Harder said:
The Boxio and Trelino look darn near identical. Any ideas on why to pick one of these over the other?
Both will get the job done - with the Boxio being half the price of a Trelino EVO M.

The Trelino looks to have a more comfortable seat design. It is a one piece design covers the side walls. I like it.

In addition to being able to use a plug, the Trelino urine container has a silicone one way valve, a.k.a. membrane, that is easily replaced.
TacomaAustin said:
Both will get the job done - with the Boxio being half the price of a Trelino EVO M.

The Trelino looks to have a more comfortable seat design. It is a one piece design covers the side walls. I like it.

In addition to being able to use a plug, the Trelino urine container has a silicone one way valve, a.k.a. membrane, that is easily replaced.
thx for the recap and info. we moved from a pop up to a van, and keep looking for options to traditional rv van setups.
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