Photo of a SunMar Composting Toilet - courtesy of Buyer's Guide to Composting Toilets
Are They A Septic System Design Alternative for Difficult Sites?

  • COMPOSTING TOILETS - CONTENTS: Guide to types, brands, and sources of composting toilets -directory of composting toilet manufacturers, models, features, uses. How to choose a composting toilet, what questions to ask, what features you need, where to install the toilet, how much space is neeed, elecricity, heat, special supplies, cleaning & service requirements. Bulk & mulch alternatives.
  • POST a QUESTION or READ FAQs about buying, using, & maintaining a composting toilet

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Composting toilet guide: this article describes the nature of composting toilets, how they work, how they are used, where they can be used, usage restrictions, and different composting toilet types and features. We define & describe just about every composting toilet type, feature, methods of operation, & maintenance requirements as well as costs. We list sources of various models of composting toilets and compare composting toilet model features, uses, and costs. We include a table of composting toilet supplies, uses, properties & prices.

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Guide to Buying, Using, & Maintaining a Composting Toilet

What is a Composting Toilet?

A composting toilet is a self-contained unit (not connected to a septic or sewer system) which breaks-down and dehydrates human waste to a compost which can be added to soils. The toilet will consist of a place to sit (which is likely to look a lot like any other toilet), a composting chamber which breaks down and sanitizes the sewage, and a drying chamber or tray which permits moisture to escape, reducing the sewage volume.

Composting toilets come in models which use a little water or no water at all, and in electric (heated and power-vented) models and non-electric models. Some models include electro-mechanical mixers which mix waste in with a mulch product to speed and improve the composting process. Properly designed and installed the toilet is vented so that there are no abnormal toilet odors. Periodically the compost must be emptied and on occasion toilet components are cleaned.

People use the toilet in a normal manner, and modern composting toilets in fact look pretty familiar, resembling water-based toilets in general shape and comfort. Waste is mixed with a "starter mulch" to begin the composting process. Composted waste is emptied from the toilet at intervals ranging from one or two months to 12 months depending on level of usage and toilet design.

Composting toilets which do not mix new human waste with material already being composted produce a compost which is easier and safer to handle. This is a reason that some models use multiple containers or compartments, though there are other solutions to this problem. If the visible portions of the toilet need cleaning, normal household cleaner and toilet brush are used.

Composting Toilet Selection Question List

The following questions one asks when considering installing a composting toilet are addressed in the article below:

  • WHEREwill the composting toilet be used?
  • WHEN will the composting toilet be used? Part time, full time?
  • HOW OPERATED depending on who is using the toilet you'll choose between manually-operated toilets, semi-automatic, or fully automatic operation of the composting unit and other features. And the smaller composting toilet units, depending on usage level, will require more frequent attention. This is also a "WHO" question as different user populations will be more or less happy doing maintenance tasks
  • OPERATING REQUIREMENTS for composting toilets include
    • ELECTRICAL SERVICE is there electricity available? 120V, 12V, solar, or none? Composting toilet models include non-electric as well as various electrical models that operate the composter, operate ventilating fans, and in freezing climates provide heat
    • SPACE AVAILABLE for the composting toilet system is important for small cabin, buildings with no basement or easily-accessible crawl area
    • CLEANING & MAINTENANCE requirements exist for all toilets, but details and frequency of cleaning, emptying the compost, operating the compost mixing feature, and other tasks vary by design and toilet capacity
    • COMPOSTING TOILET SUPPLIES - provides a table comparing supply requirements & costs. All models require some form of composting bulk medium: sawdust, peat moss, or specially prepared products. Some people try wood chips - which IMO are not likely to work well in most designs and can clog or break others,
  • FEATURES of the composting toilet
  • REGULATIONS: composting and other alternative toilet designs are regulated in some jurisdictions.
  • SOURCES: list of composting toilet manufacturers, brands, sources. Some of these manufacturers include helpful product choice guides right on their websites, and some also sell composting supplies for their toilets.

Where are Composting Toilets Most Often Used?

Composting Toilets may be used where the water supply is limited or not available at all, or where a building owner for other reasons wishes to conserve water use. Other wastewater treatment will still be required for handling graywater from sinks and showers. Shown above is the SunMar compact composting toilet. SunMar composting toilets and toilet models by other manufacturers are described below.

Full-Time and Part-Time Usage Composting Toilets

The buyer should consider carefully their intended maximum usage level of the toilet before choosing a composting toilet model.

Full time composting toilets are intended to serve as the main toilet in a full-time occupied building (more than 5 days continuous use, for example).

Part time composting toilets are intended to serve buildings which are not occupied full time (that is less than 5 consecutive days) or by some manufacturers, these models are intended for use during limited hours per day (10 or less).

Electric vs. Non-Electric Composting Toilets

Electric models include heaters to aid the composting, possibly a power ventilation system, possibly a system which mixes air in with the compost to improve the aerobic bacterial breakdown of waste, and possibly a mixing mechanism to mix sewage with mulch to aid the composting process.

Non-electric composting toilets may also be vented but will lack a heater and power mixing.

Water and Electricity for Composting Toilets

Composting toilet models vary among waterless, low water, and foam flush units. Obviously a water-model requires a water source.

Composting toilet models also vary between models requiring electricity (typically 110V), battery operated (12V), possibly solar powered, and models which use no electrical power. Features such as automatic mixing, aeration, and vent fans will require electricity

Automatic, Semi-Automatic, and Manual Composting Toilets

PHOTO of the Excel composting toilet by SunMar

A fully automatic composting toilet will typically control a heater, ventilating fan, and a mixer to mix sewage and mulch together. A fully automatic toilet mixes each time the seat is lowered.

A semi-automatic composting toilet will still use a thermostatically controlled heater, fan. But the sewage-compost-mulch mixer is manual, typically providing a handle that is turned a few times after each use of the toilet.

[Click to enlarge any image]

The compost process involves biological breakdown of the waste - a process that needs oxygen (air) heat, and some moisture. Waste/compost/mulch mixing (the traditional "turning of the compost pile") is used to improve the aerobic breakdown of waste pathogens, to macerate the waste (which aids breakdown), to be sure that all parts of the sewage are heated and treated, and to speed the composting process.

Not all composting toilets use a compost/sewage/mulch mixing mechanism, and composting toilet manufacturers do not all agree on whether or not mixing is required. The Humanure Handbook by Joseph Jenkins has an article discussing this topic [] [Envirolet has posted his article at their website].

Shown at page top is the SunMar Excel™ composting toilet. SunMar provides low water and no-water composting toilets. Image courtesy of and SunMar.

Composting Unit Size and Features vs Maintenance Needs

Smaller composting units, especially smaller units which do not use heaters and aerators, because they risk unwanted liquid accumulation, insects, and nitrification of the waste, will require more maintenance and care than units which provide an aerator fan, heater, and compost mixer.

Toilet Trap/Bowl-Closure Methods

Because some folks don't want to look into the sewage/compost in a self-contained composting toilet, and also for odor control and sanitation, all composting toilets have some method of closing off the bottom of the bowl from the waste line or composting receptacle.

Some composting toilet models use an automatic trap closing mechanism which appeals to people who don't want to operate any unfamiliar controls on their toilet.

Other composting toilets use a manual valve to close the bottom of the bowl. The manufacturers of composting toilets which use a manual valve point out [Envirolet] that men who are accustomed to urinating while standing up will have to sit to urinate on toilets which provide an automatic bowl valve.

Watch out: we've come across composting toilet user reviews complaining that the bowl closing door design looked great (automatic when the seat was lifted) but proved flimsy or actually broke quickly when the toilet was in service.

Note: we have not quoted specific reviews griping about shoddy products, clogs, breaks, and snafus or poor service because of uncertinty about the review source, authority, etc. But it's worth reading a few of these when sorting out composting toilet features and maintenance and repair performance.

Composting Toilet Waste Process Methods - Batch vs Continuous

Composting of sewage in a composting toilet involves worm processing, micro-organism processing (bacteria, molds, and possibly other microorganisms) and dehydration by the evaporation of moisture.

The toilet manufacturer may recommend or provide a specific mulching product to aid the composting product and probably to aid in deodorizing.

Batch System Compost Toilets

A batch-system composting toilet interior contains multiple or change-out composting compartments. When a compartment (or change-out container) is filled with waste it is sealed and taken out of use to permit the sewage breakdown to continue. When the composting process is complete for a given container it is emptied (and presumably applied to soil in a legal manner) and the container is returned to use.

Continuous Composting Toilets

A non-batch, continuous composting toilet receives waste continuously into a single container. The composting procedure reduces the volume of the waste which is eventually (typically after 6-12 months) removed from the bottom of the container and is considered "fully composted material" which is then emptied (and presumably applied to soil in a legal manner).

Compost Toilet Installation Space

Be sure to review the installation requirements for the composting toilet you're considering. Some models require that the toilet be installed directly over the composting reservoir and others not; some models use a large reservoir below the toilet, others may be much smaller and self-contained.

This makes a big difference if you're considering a composting toilet in a one story building built on a slab, particularly if your toilet installation space does not include space for an along-side composting tank.

In a non-freezing climate it may be feasible to add-on a shelter against a building wall to contain the composting unit, but in freezing climates where the composter needs to be protected from freeze damage (varies by model) placing the composting tank outside the building envelope increases the installation cost as well as risks of freeze damage.

When planning for space for a central composting unit (using a composting tank that is separate from the toilet itself) remember that you're not going to just jam the composter into an inaccessible crawl area. Access needs to be easy, safe, and comfortable, as regular access will be required for cleaning, emptying, and other maintenance chores.

Compost Toilet Operating Requirements

  • Ordinary toilet tissue can be used in composting toilets; we read some reviews complaining of clogging in the composter: I suspect the clog issue is more around excessive tissue use, wrong bulk media (wood chips for example), or inadequate manual operation of a mulcher/rotater in the composting mulch mixture.
  • Electrical power: 120V electricity is required for some, not all models of composting toilets. Models of composting toilets are available that operate on no electricity at all, or that can use 240V, 120V, 12-V, or solar power. Electricity may operate a vent fan, a composting mulcher, liquid pumps, or freeze-protection heaters.
  • Heat & freeze protection: Ambient temperature in the room where the toilet is used (at least for some models) must be above 64 deg F when the toilet is being used. At least some models permit the temperature to drop (presumably below freezing?) during periods when the toilet is not in use. Composting is unlikely to proceed at low temperatures, a condition which may affect the level of usage allowed and the length of time for composting to complete.

    Watch out: some composting toilet models may not work in freezing conditions, or may be damaged, or may require a heat source. Look for this detail in the product literature when choosing a model.
  • Compost disposal: periodically the composted waste is removed for disposal. It may be placed around trees and flowers or shrubs, but the owner needs to comply with local codes in this matter.
  • Liquid waste disposal: Watch out: a number of the composting toilet models we've reviewed may not emphasize or state clearly the liquid waste handling features of the system.

    Handling urine can be a problem in some designs where storage space is limited or where excessive urine liquid waste levels have to be addressed separately. Maybe in the backwoods you're fine with peeing on the ground behind the cabin, but in many installations simply routing excess liquid waste out through a wall won't work or may violate local codes. In a climate subject to freezing we don't want to be faced with an overflowing composter because a pee overflow line froze.
  • Toilet cleaning: occasionally the exposed parts of the toilet will receive normal cleaning. Don't use bleach, which in a composting toilet would damage the composting organisms and may stop the composting process. Because most composting toilets are made of either plastic or fiberglass use of abrasive cleaners is probably a bad idea as well.
  • Service & repair of composting toilets: Watch out: we were disturbed to read that a few composting toilet distributors provided very poor service, repair advice, and even worse warranty coverage. Problems seemed worse when a single "mom and pop" business was operating as the sole importer for a brand of composting toilet made in another country. Take a look at user reviews of the toilet brand and model you're considering buying.

Regulations and Standards for Composting Toilets

The U.S. standard for composting toilets is NSF (National Sanitation Foundation) Standard 41. Some, probably not all, models advertised have been tested to determine if they meet this standard. In Canada, the CSA- has adopted and also certifies composting toilets to meet National Sanitation Standard (NSF-) Standard-41.

The following is from: New York State Appendix 75-A.10 Other systems

These units shall be installed in accordance with the manufacturers instructions. The units shall have a label indicating compliance with the requirements of National Sanitation Foundation (NSF) Standard 41 or equivalent. Only units with a warranty of five years or more shall be installed.

List of Sources for Composting Toilets and Composting Toilet Brand & Model Comparisons

Composting Toilet Product Index & Feature Guides

  • Biolet composting toilets
  • Centrex composting toilets
  • Clivis Multrum composting toilets
  • CTS composting toilets
  • Eco John composting toilet
  • Eco Tech Carousel composting toilets
  • Eco Toilets (New Zealand) composting toilets
  • Enviroletcomposting toilets
  • Natures Head composting toilets
  • Nature Loo (Australia) composting toilets
  • Phoenix composting toilets
  • Sun Frost composting toilets
  • Sun Mar composting toilets
  • Sun Mar Canada: LetsGoGreen composting toilets
  • ThetfordComposting Toilets
  • CONTACT Us to list your product or service here - if you are a manufacturer of composting toilets or other alternative wastewater treatment system equipment your product may be listed at no fee. Website content critique, additions, and suggestions are also invited. has no financial nor business relationship with products or services discussed here.

Biolet composting and waterless toilets

Photo of a Biolet composting ToiletBioLet Toilet Systems 830 West State Street Newcomerstown, OH 43832, Tel: 800-524-6538, Website:

  • Biolet 10 Standard Waterless Toilet, $1,800. Fan, thermostatically controlled heater, and a handy manual mixing control, Rated: 3 people full time or 4 people part time use. Cottage, basement, barn, etc.

  • Biolet 20 Deluxe Waterless Toilet, $2000. Fully automatic composting toilet. Thermostat, fan, automatic mixer, automated liquid controls. Rated 3 people full time, 4 people part time.

  • Biolet 60 XL Waterless Toilet, $2,500. Swan Ecolabel certification. Extra capacity. Thermostat, fan, automatic mixer, automated liquid control.

  • * Biolet Swedish composting toilets ranging from fully automatic electric composting BioLet 60 XL (4 people full time use) Composting toilet prices: $2000. U.S. to a non-electric BioLet 30 NE model (3 people full time use) $1400. U.S. Smallest model: $1000.

  • * BioLet XL composting toilets available from BioLet (link above) and from EcoTech (link at left - EcoTech is a supplier of composting toilets including the BioLet series) are intended for cottages, extra rooms, and remote buildings. The unit includes a mixing motor, heater, and fan. BioLet toilets are available from the manufacturer and from various composting toilet suppliers. EcoTech also offers a urine-diverting toilet to expand the capacity of a composting toilet system, construct a drying toilet, and to provide source denitrification of sewage waste.

  • BioLet 30 NE Non-Electric Waterless Solution Biological Toilet,
    With over 30 years of Swedish engineering experience, BioLet has released the 5th generation of their self-contained composting toilets. Constant advancements in their products have resulted in BioLet being the most advanced, easiest to use, easiest to install, self-contained composting toilet system in the world. Designed for locations where reliable electricity is not available, the BioLet 30 NE is the perfect choice for the rustic cabin, hunting camp, or house off the grid. The BioLet 30 NE is also the perfect choice for applications supplied by solar power where the additional load of the electric models may be too much for your system. Rated at 3 people full-time use and 4 people part-time use, the 30 NE's capacity can be increased to 4 people full-time use and 6 people part-time use by adding the auxiliary 12VDC fan.

    Equipped with a convenient drain tube, the 30 NE drains off the excess liquids to an auxiliary container, French drain or leach field. Since liquids are not a limiting factor, the 30 NE will allow for applications where a larger capacity may be needed. When the compost bin fills, just transfer the humus to an auxiliary compost container outside for further composting. As with all BioLets the 30 NE is easy to install by anyone with basic handyman knowledge in just a couple hours with common household tools.

    BioLet 30 NE Non-Electric Waterless Solution Biological Toilet Features:; 3 people full-time use (4 people with auxiliary fan), 4 people part-time use (6 people with auxiliary fan); Installed: Height - 25", Seat height 19.5", Width - 15.75", Depth - 29"; Completely sealed casing of ABS - plastic. Mixing arms and other important metal components of stainless steel.; Box Includes: o 1 - BioLet 30 NE Composting Toilet o 1 - 8 gallon bag Starter Mulch o 1 - Auxiliary compost bin o 1 - Winterizing plug o 1 - Manual mixing rake o 5 - 2' sections


Centrex Composting Toilets

Centrex 1000 composting toilet from SunMar Photo of the Centrex 2000 A/F central-flush waterless air flow composting toilet which uses
a below-floor composting drum - a composting toilet
  • Centrex central flush composting system (images just above) Available in three batch unit sizes & 1 continuous-use unit used with 1-pint flush toilets. Available in electric (120V or 12V) and non-electric models.

    Liquid output is drained separately and needs to be directed to an approved facility.

    The Centrex line is available from Sun-Mar Products, (requires under-floor space for the composting unit)
    • BuyGreen - (retailer)
    • Sun-Mar Corp. 600 Main St. Tonawanda, NY 14150, USA, Tel: 1-888-341-0782, Tel, International: 905-332-1314, Email:
    • Sun-Mar Corp. 5370 South Service Rd. Burlington, ON, L7L 5L1 Canada

Clivis Multrum Composting Toilets

Sketch of the design for a Clivus Multrum composting Toilet
  • Clivus Multrum composting toilets have been around long enough to be famous. (The Clivus Multrum composting toilet was invented by the Swede Richard Lindstrom in 1938.) Toilet models include a central composting system design, a waterless design and a foam flush design.

    The foam flush model does not have to be directly over the composter. The low water system automatically adds water to the composter.

    Clivis describes an integrated outbuilding restroom design too. The company offers factory technician maintenance service for the composter (which appears larger than some competing units, but CM may have other smaller models).

    This system uses a lower-temperature decomposition process known as moldering, which takes place slowly over several years and for this reason involves a comparatively large composting unit, manual liquid removal, and steps to address persistent pathogens or pests that may develop in the composter. Prices: $2500 - $5000. Clivus Multrum offers other wastewater disposal systems and products such as a greywater system which we discuss at our greywater information article.

CTS Composting Toilets

Photo of CTS composting Toilets - a bunch of them being transported
  • CTS - Composting Toilet Systems six models, large below-toilet composter, built-to-order using fiberglass and plywood. Website does not quote prices. CTS also distributes Sun-Mar. Compost Toilet Prices $4600. to $5300. plus additional charges for support kit, solar-operated vents, fire suppression system.


Eco Toilets - New Zealand composting toilets
Sketch of the Toatrone waterless composting toilet from Eco Toilets in New Zealand.

  • Eco Toilets (New Zealand) Composting toilets for permanent dwellings as well as for holiday homes. Flushable Toilets, Non-flushable Toilets - Composting and Electric Toilets. EcoToilets Toatrone (shown here) is a non-flush waterless toilet which also performs urine separation.

    The composting reservoir is placed directly below the toilet. EcoToilets informs us that this composting toilet design is derived from the earlier Clivus Multrum composting toilet design.

    In this Eco Toilets composting model, a special "air staircase" allows air to penetrate through the composting sewage waste from below, a detail which the designer says makes the process of decomposition very efficient. Usage level: designed for permanent living.

    A normal household would remove waste as compost once a year. Eco Toilets also offers Aquatron flush composting toilets which use urine separation, flushing, and a composting container. Eco Toilets is located in Hamilton, New Zealand

Carousel Composting Toilets - EcoTech

Photo of a Carousel batch process composting Toilet
  • * Carousel batch composting toilets from EcoTech include self-contained and under-floor models. Composting waste is kept separate from in-use toilet. Similar to the Norwegian Vera (TM).

    Prices: $2200. to $3400. U.S.



Eco John Composting Toilets - U.S.
Photo of the EcoJohn Basic - A waterless separating composting toilet

  • Eco John EcoJohn Basic - A waterless separating composting toilet, which is perfect where an ecologically sensitive toilet facility is desired.

    Few product details were at the Eco John toilet website. This is a California company not the New Zealand listing just above.
  • Eco-San, low density polyethylene, waterless urinal, wind-turbine vent system, outside composter attached to the toilet. Composting toilet price $3000.

Eco Toilets, Composting Toilets, New Zealand

  • EcoToilets (New Zealand), Ecotoilets, PO Box 7257, Te Ngae, Rotorua 3042 New Zealand 57 - 77 Wahanga-a-Rangi Cres, Eastgate Industrial Park, Te Ngae Rotorua New Zealand Phone: +64 (7) 349 4940. Composting toilets with urine separation. Website: [Swedish technology] The below-floor composter in this design feeds liquid waste into gray water tanks that feed a leach field.

    The company also provides an Aquatron low-flush toilet and composter system and a Toatrone waterless toilet developed from the original Clivus Multrum 1938 design. A smaller eco-solution re-locatable toilet uses a smaller composter that is emptied on 6-month intervals and can be equipped with a solar-powered vent fan. No prices are quoted but a fully operational system target is $10,000. NZ.

Envirolet Low Water & Waterless Toilets & Composting Toilets

Photo of an Envriolet self contained composting toilet
  • Envirolet Waterless Remote Composting Toilet System (120v Electric)
    The Envirolet Waterless Remote System (120VAC Electric) is ideal when you have space directly below your bathroom either in a basement or outside. The Waterless Toilet goes in your bathroom and is connected to the Waterless Remote System (shown above). The highest capacity Envirolet System available. This System was feature in the Field & Stream "Dream Cabin" magazine! Included with system purchase: 1. Envirolet Waterless Remote (120VAC Electric) Composting Unit 2. Waterless Toilet (White) 3. Premix Starter Kit 4. Envirolet Compost Accelerator (8oz) 5. 4" Wind Turbine 6. Vent/ Drain Kit (Includes: 2' x 8" Flexible Drain Duct, 8" Gear Clamp, 4' x 4" Flexible Vent Duct, 4" Coupling, 4" Gear Clamp, Silicone, and Rubber Roof Flashing.
  • Envirolet Low Water Remote Composting Toilet System (120v Electric)
    The Envirolet Low Water Remote (120VAC Electric) Composting System has the highest capacity of all the Low Water Remote Systems and allows for up to three toilets to be connected to the composting unit. Each Low Water Toilet flushes with as little as one pint. Included with system purchase: 1. Envirolet Low Water Remote (120VAC Electric) Composting Unit, 2. Premix Starter Kit, 3. Envirolet Compost Accelerator (8oz), 4. 4" Wind Turbine, 5. 2-Stage Pre-Sediment Filter Drain Kit (Filter Tray, 5' Nylon Drain Line Quick Connect Breather "T"), 6. Luxury Low Water Toilet (White), 7. Vent/ Drain Kit (3' x 3" Flex Drain Duct, 4' x 4" Flex Vent Duct, Gear Clamps, Water Supply, Floor Flange, Coupling, Silicone, and Rubber Roof Flashing)
  • Envirolet Waterless Toilet (Black Granite), This toilet is easy and sanitary to clean with its removable bowl. Used with Envirolet Waterless Remote Composting Toilet Systems, but can also be used with existing outhouse or other composting toilets -- not that anyone would choose anything other than an Envirolet! This toilet is 16.5" W x 22.5" L x 20.5" H (15" height to seat). Waterless toilet (black granite), toilet seat (oak), rubber floor gasket and hardware included
  • Envirolet Waterless Toilet (Cream)

LetsGoGreen - SunMar Canada

  • LetsgoGreen is not a toilet manufacturer but rather a Canadian supplier of SunMar and other electric and non-electric versions of composting toilets (Ontario, Canada).

    The toilet shown here is the Centrex 2000 A/F central-flush waterless air flow composting toilet which uses a below-floor composting drum (110V, Composting Capacity: 4-6 Residential, 6-8 Weekend/Vacation Use, cost $1,795.00). Other self-contained composting toilet models are available.

Nature's Head composting toilets Nature's Head composting toilet

  • Nature's Head is a U.S. made stainless-steel composting toilet, designed originally for the marine environment (use on boats). This is a portable, self contained, urine separating dry toilet that can be used where electricity is not available. The liquid waste compartment can store 2.2 U.S. gal. which the manufacturer recommends disposing of in a public restroom.

    Liquid urine waste is automatically separated from the solids. Solid waste that has composted (decomposed) for 3 months or more can be used as plant fertilizer; solid waste that has not composted that long can be bagged and disposed-of in a dumpster. The base product cost is about $850.00 U.S.

    The manufacturer notes that the toilet system does not produce the odors associated with holding tank toilet systems. It is suitable for cabins, cabanas, boat houses, hunting camps, RVs, basements, semi-trucks, and even pick-up trucks. The unit is vented to outside a venting kit chosen depending on the installation requirements. A 12-V fan is used to operate the ventilation system, powered by battery or a solar vent with backup solar-charged battery pack.The composting
    system is primed with damp, crumbly peat moss. Telephone: 251-295-3043 email:

  • 3/7/2014 Alan Morton said: Nature's Head Composting Toilets are now available ex-stock in New Zealand from the sole importing agent - The Outdoor Shop, 2 Cobham Road, Kerikeri, Bay of Islands. Phone: 64-(0)9 - 4077641 or email or

Nature Loo Composting Toilets, Australia

  • Nature-Loo composting toilet is an Australian product includes ceramic and plastic models. Available in both full time & part time use models & models for mobile homes & boats. For homes & extensions, available in split systems for non-slab-floor installations & self-contained systems for slab floor installation.

Phoenix Composting Toilets

  • Phoenix Composting Toilet from Advanced Composting Systems (195 Meadows Road, Whitefish, MT 59937), requires 5 watts of electric power. Hand pump to remove excess liquid; rotating tines to move compost to the removal area. DC fan; can run on photovoltaics.

    Phoenix Composting Toilet Prices: $4100. to $6100.Email:, Website: Internet:
    Also available from Sunergy Systems Ltd., Box 70 • Cremona, AB T0M 0R0 Phone/Fax: 403-637-3973
    Operating Manual:

Site-Built Composting Toilets

Shown below is a composting toilet system in use above Akaroa at the Hinewai Reserve (Maurice White Native Forest Trust) on the Banks Peninsula in New Zealand. Using a combination of purchased and site built components this composting toilet serves hikers and visitors to the preserve.

Composting toilet, Hinewai Reserve, Akaroa New Zealand (C) Daniel Friedman

Separate toilet facilities or latrines for urine are provided for use if the liquid level in the composting toilet becomes too high but at the time we visited this facility a note from the management encouraged peeing into the composting toilet as the mixture was too dry.

Composting toilet, Hinewai Reserve, Akaroa New Zealand (C) Daniel Friedman Composting toilet, Hinewai Reserve, Akaroa New Zealand (C) Daniel Friedman

At above left is the box of dry plant material, of which a small handful is tossed into the composting loo after each use. At above right we see that this composting loo includes a ventilating fan that can be switched on if the composting toilet is a bit smelly.

Sun Frost Human Humus Composting Toilets

  • Sun Frost "Human Humus Machine" Composting Toilet, Sun Frost, Sun Frost 824 “L” Street Arcata, CA 95521, Tel: 707-822-9095, Email:, Website: Pricing not found at website. Quoting:

    The Human Humus Machine is available in a relatively low-cost kit form. The kit consists of all the parts necessary to convert two 55-gallon drums into a state-of-the-art composting toilet. The drums have a plastic liner to eliminate rusting. The kits are easy to assemble and can be completed in less than 2 hours. The installer would obtain the drums locally. We can also offer fully assembled units.

    The Human Humus Machine is a batch-type CT. After the drum is full, the contents of the drum are allowed to sit for a number of months to complete the composting process. In non-batch type composters, newly deposited material can contaminate compost ready to be removed.

SunMar Composting Toilets

Photo of a composting Toilet
  • * SunMar provides low water and no-water composting toilets, and stand alone toilets as well as equipment to provide central composting supporting multiple toilets. (Their website says there are 20 models of low water or no water toilets.)

    SunMar uses a rotating drum to mix the compost. Sun-Mar is described by some vendors as not a true composting toilet but as a "dry toilet", smaller than true composting toilets, and using supplemental heat, air, and mixing to assure waste decomposition. Waste is kept on an outside compost pile for six months before spreading on soils.

    More frequent emptying and smaller capacity than "true composters" this toilet may be a best fit for a low-use remote cabin. SunMar offers a variety of composting toilets including a self-contained composting marine toilet model, the SunMar Mobile, certified by the U.S. Coast Guard ($1,489.00). Shown here is the SunMar Excel ne composting toilet [Click image for larger photo]. SunMar composting toilets are described below.

Thetford Composting Toilets

  • Thetford Corporation 7101 Jackson Road, Ann Arbor, MI 48103, Phone: 1-800-543-1219, 734-769-6000, Fax: 734-769-2023; Thetford produces a wide range of permanent and portable alternative toilet designs. Quoting:
    Our [toilet] products are easy to use at bedside and indispensable for the physically challenged, the aged, and small children.
    Thetford's list of toilet products suitable for home or bedside health care are listed at

    * - units that were recommended by RealGoods and which look good to us.

Table of Composting Toilet Operating Costs, Choices, Supplies - do we really need to buy mulch or sawdust or other stuff?

Reader Question: What are the operating costs & choices for composting toilets? Are consumables really required for composting toilets?

Your web site has been very useful indeed but we remain uncertain about our choice. Are you aware of a composting toilet that uses water and standard house electricity for which there are no consumables necessary? if not is there a way of comparing the on-going costs of additives for these toilets? Thanks very much - A.D. - Canada

Reply: List of Composting Toilet Supplies, Costs, Features, Functions

I am not aware of any composting toilet design for which the manufacturer recommends no consumables whatsoever. The minimum consumable required is a bulking material. Sun-Mar and some others also offer enzymes, deodorants, and compost activators that may be optional. Quoting from the Phoenix Composting Toilet System Instructions for Operation and Maintenance, and noting that opinions vary among manufacturers about the best and most easily biodegraded bulking material to use in a composting toilet:

Bulking material is necessary to improve drainage and aeration, and to provide extra carbon, thus creating conditions essential for composting. The right amount of bulking material gives the compost pile a crumbly, porous texture. An inadequate amount results in a wet, pudding-like texture, puddling liquid, and anaerobic conditions that generate an unpleasant odor. [1][2]

"Anaerobic conditions" means more than just an unpleasant odor. It also means the system will lack aerobic bacterial action and biodegradation will not proceed properly nor adequately.

Keep in mind that the operating cost for a composting toilet depends not only on the cost of supplies but on the type of toilet selected (non-electric vs. electric, for example) and upon the level of usage and perhaps maintenance. That said, below we have begun a table of composting & waterless & low-water toilet system supplies, uses, & costs.

Table of Toilet Supplies for Composting, Low-Water & Waterless Toilets

The toilet supplies listed in the table below are available from the manufacturers listed in a product directory found in the article above, as well as from additional distributors located online.

Composting Toilet Brand & Supply Item
Quantity Properties Usage
Biolet Compost Starter Mix $30. 8 gal. bag A specialized compost mix of peat and other natural organic materials help keep your BioLet composting toilet at its peak efficiency. Formulated by soil scientists, this mixture provides the optimum balance for efficient composting.

1 bag will last 2 people using a BioLet full time for about 3-4 months.

add 1/2 cup of this compost mix after each fecal use



New Zealand

      nothing listed
Envirolet® Starter Mix Kit $32.
2 for $59.
1 bag of premix starter material and 1 paper mat activates the composting process. Recommended for seasonal start up of your Envirolet® composting toilet system or any other type of composting toilet system. not found
Envirolet Compost Accelerator




1 x 16 oz jar Applied to Envirolet® composting unit once every two weeks with a small amount of warm water.

Helps accelerate the composting process in your system. Take advantage of the quantity discount! Can even be added to your home or backyard composter.
16oz jar will last approximately 9-12 months when using 1 tablespoon every 2 weeks with a warm cup of water.
Envirolet Daily Mix Reusable Pail $43.

56 Cups Daily Mix in Reusable Pail Daily Mix is specially formulated for daily use with Envirolet® Composting Toilet Systems. Improves composting and is recommended instead of peat moss. All natural material. 1/4 cup per user of Daily Mix every day evenly over compost
Envirolet Daily Mix Refill Pak for above item $94.

6 bags. 168 cups see above see above
Envirolet Air Solution Kit



3 gel cassettes per kit

Cassette is placed inside system between Aeration Basket and shell of body.

Helps ensure a fresh outside scent. Particularily helpful in low lying areas or areas where trees may result in a downdraft.

Each cassette will last approximately 30-60 days

Nature Loo
Nature Flush Enzymes


$32 AUD 1L

$140 AUD 5L
1L or 5L of concentrate, dilute 20 parts water to 1 part enzyme concentrate .

Enzyme Concentrate –
To speed up the composting process and provide a fresh fragrance with the push of a button, enzymes can be sprayed into the chamber.

In the case of the Compact toilet you can either add these manually using a hand held domestic spray flask or by purchasing our micro dosing pump kit, which produces an evenly distributed spray directly onto the contents of the chamber.


Kits contain a micro flush foot pump, storage container, pipes, nozzles and enough enzyme concentrate for 4000 flushes.
Phoenix composting toilet bulking mix see note at right  

The best bulking material is dry planer shavings from a white softwood
such as pine.

Do not use shavings from decay resistant woods such as cedar or redwood: this material will reduce the composting rate.

The bulking agent must have a physical structure that resists compaction so that air voids will remain open.

Do not use large wood chips, wood waste from treated lumber, or materials that form a mat, such as long grass or leaves. Dry pine shavings often are sold as bales of animal bedding.

Add one to two gallons of bulking material
through the toilet or upper access door for every 100 uses.

Add one to two gallons of bulking material
through the toilet or upper access door for every 100 uses.

Sun-Mar® Compost Sure - BULK $75 list

avail at $60
One Bulk package = 5 boxes of 8-gallon (30L) bags Comprised of peat moss & chopped hemp stalk. Quoting: Compost Sure consists of coarse peat moss and chopped hemp stalk. Compost Sure has an added advantage over homemade bulking material - hemp. Hemp will decompose where wood shavings and peat moss do not - giving your compost a longer residency time! More importantly, it saves you the time of making your own mix. 1 cup of compost mix per person per day or 1 cup of compost mix for every bowel movement.
Sun-Mar Compost Sure Blue - BULK $75-$90 One Bulk package = 5 boxes of 8-gallon (30L) bags Bulking material containing 100% hemp stalk. Designed especially for central systems with low-flush toilets in addition to garden composters. The hemp stalk breaks down quickly while offering good porousity and keeps the compost supplied with carbon. ?? - copy from above 1 cup of compost mix per person per day or 1 cup of compost mix for every bowel movement.
Sun-Mar Compost Quick Spray



12/ 16oz. bottles of spray enzyme. Enzyme liquid accelerates the composting action, leaving you with a perfect finished compost every time. It can also be used as a cleaner for either your bowl liner (for self-contained models) or your toilet (for Low Flush systems). 3-4 squirts of nozzle before rotating drum. We estimate that translates into 200+ squirts/bottle or 25 drum rotations.
Sun-Mar Microbe Mix $17. 16 oz jar Super-biologically active bacteria which will recharge your compost.  


1. Prices are rounded to nearest dollar

2. Fast dissolving toilet tissue & other supplies are excluded from this list unless specified as required by the toilet manufacturer.

3. Bulk additive for composting: reading reviews of what works and doesn't work for people we note that

- Sun-mar advised an unhappy owner of a Centrex composting toilet that their soggy waste mixture was caused by failing to use the proper mix of sawdust and peat moss - (retrieved 2/24/2014 2014)

- Watch out: do not use home-made bulk composting remedies like wood shavings or wood chips; you're likely to clog and possibly damage the composting mixer as well as to see poor results in the field.

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