This process leads to the decomposition of organic matter and turns human waste into compost-like material.

In many composting toilet designs, a carbon additive such as sawdust, coconut coir, or peat moss is added after each use.

[2] Common applications include national parks, remote holiday cottages, ecotourism resorts, off-grid homes and rural areas in developing countries.

They can also help increase the resilience of existing sanitation systems in the face of possible natural disasters such as climate change, earthquakes or tsunami.

These types of toilets can be used for resource recovery by reusing sanitized feces and urine as fertilizer and soil conditioner for gardening or ornamental activities.

Adding small amounts of water that is used for anal cleansing is no problem for the composting toilet to handle.

Waste-derived compost recycles fecal nutrients, but it can carry and spread pathogens if the process of reuse of waste is not done properly.

Pathogen destruction rates in composting toilets are usually low, particularly of helminth eggs (such as those from the genus Ascaris).

[8] High temperatures or long composting times are required to kill helminth eggs, the hardiest of all pathogens.

In thermophilic composting bacteria that thrive at temperatures of 40–60 °C (104–140 °F) oxidize (break down) waste into its components, some of which are consumed in the process, reducing volume and eliminating potential pathogens.

[3] An alternative guideline claims that complete pathogen destruction may be achieved already if the entire compost heap reaches a temperature of 62 °C (144 °F) for one hour, 50 °C (122 °F) for one day, 46 °C (115 °F) for one week or 43 °C (109 °F) for one month,[6] although others regard this as overly optimistic.

Some commercial units include a urine-separator or urine-diverting system and/or a drain at the bottom of the composter for this purpose.

Commercial systems provide ventilation that moves air from the bathroom, through the waste container, and out a vertical pipe, venting above the roof.

World Health Organization Guidelines from 2006 offer a framework for safe reuse of waste, using a multiple barrier approach.

Some units use fans for aeration, and optionally, heating elements to maintain optimum temperatures to hasten the composting process and to evaporate urine and other moisture.

Operators of composting toilets commonly add a small amount of absorbent carbon material (such as untreated sawdust, coconut coir, or peat moss) after each use to create air pockets to encourage aerobic processing, to absorb liquid and to create an odor barrier.

Maintenance tasks include: cleaning, servicing technical components such as fans and removal of compost, leachate and urine.

Enriching soil with compost adds substantial nitrogen, phosphorus, potassium, carbon and calcium.

Among the medications that have been found in groundwater in recent years are antibiotics, antidepressants, blood thinners, ACE inhibitors, calcium-channel blockers, digoxin, estrogen, progesterone, testosterone, Ibuprofen, caffeine, carbamazepine, fibrates and cholesterol-reducing medications.

In the late 19th century in developed countries, some inventors, scientists and public health officials supported the use of "dry earth closets", a type of dry toilet with similarities to composting toilets, although the collection vessel for the human waste was not designed to compost.

Seven jurisdictions in North America[22] use American National Standard/NSF International Standard ANSI/NSF 41-1998: Non-Liquid Saturated Treatment Systems.

For instance: The Environmental Protection Agency has no jurisdiction over the byproducts of a dry toilet as long as waste are not referred to as "fertilizer" (but instead simply a material that is being disposed of).

[32] Most of them stipulate the use of flush toilets, however there are many exceptions, for example in the states of Hamburg, Lower Saxony, Bavaria, Mecklenburg-Western Pomerania, Rhineland-Palatinate, Saxony-Anhalt and Thuringia.

[32] These generally make exceptions for the use of composting toilets in homes provided that there are no concerns for public health.

[32] Numerous sparsely settled villages in rural areas in Finland are not connected to municipal water supply or sewer networks, requiring homeowners to operate their own systems.

For these reasons, many manufacturers of composting toilets are based in Finland, including Biolan, Ekolet, Kekkilä, Pikkuvihreä and Raita Environment.

In Germany and Austria, composting toilets and other types of dry toilets have been installed in single and multi-family houses (e.g. Hamburg, Freiburg, Berlin), ecological settlements (e.g. Hamburg-Allermöhe, Hamburg-Braamwisch, Kiel-Hassee, Bielefeld-Waldquelle, Wien-Gänserndorf) and in public buildings (e.g. Ökohaus Rostock, VHS-Ökostation Stuttgart-Wartberg, public toilets in recreational areas, restaurants and huts in the Alps, house boats and forest Kindergartens).

The settlement of 36 single-family houses with approximately 140 inhabitants uses composting toilets, rainwater harvesting and constructed wetlands.

[36] Slow composting toilets have been installed by the Green Mountain Club in Vermont's woodlands.

[37] The club also uses pit latrines and simple bucket toilets with woodchips and external composting and directs users to urinate in the forest to prevent odiferous anaerobic conditions.