REVIEW – Any overnight trip turns into a logistics exercise as soon as someone asks about the bathroom plan. I used to answer that question with a shovel joke, but the Trelino Evo S Portable Composting Toilet has given me a much better, cleaner, and far less awkward answer.
The Evo S is not a bargain bucket with a seat. At $399, it is a serious piece of outdoor kit, and after using it I understand why. Its compact body, separate liquid and solid containers, and no water, no chemical approach made camp bathroom duty easier than I expected.
What the Evo S is
The Trelino Evo S is a compact portable composting toilet made in Germany for camping, van life, boating, and other outdoor situations where a normal bathroom is not available. It separates liquid waste from solid waste, then relies on biodegradable bags and a drying medium to control odor.
The capacities are intentionally modest because this is the small version of the Evo line. The urine canister holds 1.2 gallons, and the solids container holds 1.6 gallons. Trelino lists the emptying cycle at 1 to 2 days depending on use, with liquid capacity for about 9 to 11 uses and solids capacity for about 4 to 8 uses.
In the box
- Exterior toilet body
- Seat with urine separator and soft closing lid
- Solid waste container with 1.6 gallon capacity
- Closed lid for the solid waste container
- Urine canister with 1.2 gallon capacity
- Lid with membrane closure for the urine canister
- Closed lid for the urine canister
- Biodegradable waste bags
- User manual
Specifications
- Materials: ABS and polypropylene plastic
- Width: 13 inches
- Height: 11.7 inches
- Depth: 15.4 inches
- Emptying cycle: 1 to 2 days depending on usage
- Urine capacity: 1.2 gallons, about 9 to 11 uses
- Solids capacity: 1.6 gallons, about 4 to 8 uses
- Weight: 8.6 pounds
- Weight limit: 330 pounds
Design and materials
The best part of the Evo S is how ordinary it looks until you open it. Closed, it is just a clean, dark box with a soft gray lid and minimal branding. Open, it reveals the real trick: a shaped seat that sends liquid to the front canister and solid waste to the rear container.
Separating those two waste streams is the whole point. Solid waste gets covered with a drying medium, while liquid waste is sealed in its own canister. That combination keeps smells from developing without water or chemicals, and it makes emptying the toilet less unpleasant than with many portable toilets.
The outer shell and lid use lightly textured ABS plastic. The internal containers are polypropylene. Trelino notes that both materials are recyclable and resistant to aqueous chemicals. Empty weight is only 8.6 pounds, so moving it around camp or into a vehicle is easy.
The solid waste container is rated for roughly six to eight bowel movements, though I would rather empty it more often than push it to the limit. The urine canister is simple to lift out, and the sealed cap prevents sloshing on the way to disposal.
The shell is water resistant, so Trelino says it can be used in shower areas if needed. That does not turn it into an indoor bathroom fixture, but it does make it more flexible for camp and vehicle setups.
Setup
Getting the Evo S ready is quick. Confirm that the liquid and solid containers are in the correct positions, line the solids container with one of the biodegradable bags, add a starter layer of drying material, and snap the seat back on.
Trelino suggests sawdust, coconut coir, organic peat moss, soil, or dried coffee grounds as covering material. I used inexpensive clay based litter because it was easy to buy and suited to drying and odor control. Whatever you choose, the key is to cover solid waste after every use.
Using it outdoors
During testing, the Evo S worked impressively well. Across about 8 to 10 uses, I did not smell waste. The only odor I noticed was the faint scent of the drying litter. The catch is that you have to use enough cover material. In my experience, at least two scoops after each solid use made the difference.
The separator seat does require a little awareness. Bodies are not precision instruments, and you may need to adjust your position to keep liquid in the front and solids in the back. It is not difficult, but it is something you notice when moving from a normal toilet to this style of portable setup.
Comfort was acceptable for me, but the S size is clearly compact. Bigger users, or anyone who wants a more familiar seat size, should look at Trelino’s medium or large Evo models. For tight storage spaces, the small size is the advantage.
I had read complaints that the biodegradable bags could break down too quickly, so I let my test bag sit for more than a week. It held together without issue. Using plenty of drying material likely helped, since the bag was not left sitting in wet waste.
Emptying was straightforward. The bag tied shut easily, and the urine canister lifted out by its handle. My only design gripe is the urine container shape. Because the top and sides are fairly flat, getting every last drop out takes extra tipping. A more tapered top would make that step cleaner.
What I liked
- Compact, discreet design that packs like a simple box
- Separate liquid and solid containers dramatically reduce odor
- No water or chemicals required
- Waste removal is easy and fairly discreet
What I would change
- The separator takes some conscious effort during use
- The S size may be too small for some people and some setups
- The $399 price is high compared with basic camp toilet options
- The urine canister would empty more cleanly with a tapered top
Final thoughts
The Trelino Evo S Portable Composting Toilet is expensive, but it solved a real outdoor problem in a tidy, well built way. It is light, compact, easy to move, and much less gross to manage than I expected. The small size will not suit everyone, which is why it is good that Trelino also offers medium and large Evo versions.
For camping, overlanding, van travel, or any situation where bathroom options are limited, the Evo S makes sense if space is tight and odor control matters. A cheap bucket still costs far less, but the Trelino’s separation system, soft closing lid, sturdy construction, and discreet shape make it feel like actual gear rather than an emergency workaround.
Price: $399
Product Link: Trelino
Source: The sample of this product was provided for free by Trelino.
Trelino did not have a final say on the review and did not preview the review before it was published.
