Last Updated: 17 Feb 2014

   Dry Toilets

Factory-Made Commercially Available Units

Out of the Box,
Ready to Install

While many commercially available manufactured units are designed to compost what comes down a conventional flush toilet, mentioned here are only the ones that separate the urine and remain dry.

Most of them ingeniously try to put everything needed to collect and store excreta all together in a small package.  They are designed with no vaults or external containers and can be installed just like your usual flush toilet (without the drain or water connection).

Some have particular application in RVs or boats, where space is limited; others might do well in a remote camp, cabin or lodge that has no sanitary plumbing.

Any of them could be installed in a residence.  Besides price, which can be considerable ($1-2K), issues include capacity and what one must do to empty and clean the units, and dispose of the contents.


Many different composting toilets are on the market, but only a few separate urine from feces at the toilet in the manner of UDDT (urine diverting dry toilets); the others require special drainage or sewer connection to drain off urine contaminated with feces (seep liquid).  Only examples of manufactured UDDT-type toilets are given in this section.

Biolan UDDT

Biolan Separating Dry Toilet:  Operation based on separation of the solid waste and liquid in the seat part; requires neither water nor electricity supply.   [company website:]  (Manual for this product found at )
Biolan Naturum

Biolan Naturum.  Detailed product manual at

Biolan ( ) makes a range of self-contained dry urine diverting toilets, including one that freezes the contents to -15° C, one with wheels that trash truck can pick up, very small capacities for residences. 

Website with more detail on Biolan and Separett:

Separret UDDT

Separett toilets separate the urine from the solids. The solids stay only slightly moist, and composting is said to rapidly occur. The urine  is diverted to a grey water system, storage tank or drain pit. (

Separett makes several UD self-contained toilets, also the Privi UD seat (; sold in U.S. by Ecovita

Natures Head

Nature's Head (see ) is a self-contained, waterless, urine-diverting unit for marine, RV, small cottages or a guest room. Eliminate the costly, complex, space consuming and inconvenient holding tank/ septic system.  Said to be easy to install, use and maintain, no odor. It holds about 60-80 "uses" - which could last two people all summer without emptying.

Nature's Head also has o centralized or lo-flush options (

More offerings:

Toilets for People ( Compact Rotating Aerobic Pollution Prevention Excreta Reducer. They call it the "CRAPPER".

Cotuit Dry Toilet  ( units are airtight, and they have an integral urinal which takes off the urine [also useful info on insects and mitigation, urine and poop use, ].

Dubbletten Urine Diverting Toilet uses small abount of water to flush, separates liquid and solid.

The Aquatron composting system separates liquid and solids, may be used in conjunction with either standard toilets or urine diverting toilets; small quantities of water.;

Dunster House (UK) makes eco-composting toilet (fixtures and entire wood structures) which is UDDT ( ).

Envirolet also makes self-contained, centralized, dry (waterless) or lo-flush variations, also vacuum flush ( ).  They also discuss the role of manufactured units vs. site-built units in changing attitudes towards flushless sanitation.

Various Sun-Mar models (self-contained dry and lo-flush; centralized dry and lo-flush; marine and RV) ( ).

Ekolet makes a self-contained dry toilet unit with rotating chamber. (

Ecosan waterless toilet ( is large subterranean unit, one each per toilet, with helical screw conveyer activated when toilet seat raised/lowered.

Air Head is very small self-contained UD unit (RVs and boats especially) that separates urine to drain and dries solids in container ( ).

Sustainable Organic Integrated Livelihoods (SOIL) is a US 501(c)3 protecting soil resources and transforming wastes into resources in Haiti ( Build Ecosan toilet oneself.

Peepoo bag ( is not a dry toilet but an expeditious method to capture and seal excreta for transfer to trash.

Dry-Flush ( ) is not a dry toilet, but has a bag below toilet seat with multiple twists that is put in trash.

Several “centralized” composting systems are manufactured but, it appears, none operate as UDDTs, all require separate sewer connection or seep liquid collection/processing: non-UD centralized unit.  more SunMar centralized units described and sold.