Urine, excreted by the kidneys, is a liquid containing excess water and water-soluble nitrogen-rich by-products of metabolism including urea, uric acid, and creatinine, which must be cleared from the bloodstream. Urinalysis detects these nitrogenous wastes in mammals.
In placental mammals, urine travels from the kidneys via the ureters to the bladder and exits the urethra through the penis or vulva during urination. Other vertebrates excrete urine through the cloaca.
Human waste (or human excreta) refers to the waste products of the human digestive system, menses, and human metabolism including urine and feces. As part of a sanitation system that is in place, human waste is collected, transported, treated and disposed of or reused by one method or another, depending on the type of toilet being used, ability by the users to pay for services and other factors. Fecal sludge management is used to deal with fecal matter collected in on-site sanitation systems such as pit latrines and septic tanks.
The sanitation systems in place differ vastly around the world, with many people in developing countries having to resort to open defecation where human waste is deposited in the environment, for lack of other options. Improvements in "water, sanitation and hygiene" (WASH) around the world is a key public health issue within international development and is the focus of Sustainable Development Goal 6.
Excretion is elimination of metabolic waste, which is an essential process in all organisms. In vertebrates, this is primarily carried out by the lungs, kidneys, and skin. This is in contrast with secretion, where the substance may have specific tasks after leaving the cell. For example, placental mammals expel urine from the bladder through the urethra, which is part of the excretory system. Unicellular organisms discharge waste products directly through the surface of the cell.
During life activities such as cellular respiration, several chemical reactions take place in the body. These are known as metabolism. These chemical reactions produce waste products such as carbon dioxide, water, salts, urea and uric acid. Accumulation of these wastes beyond a level inside the body is harmful to the body. The excretory organs remove these wastes. This process of removal of metabolic waste from the body is known as excretion.
Waste are unwanted or unusable materials. Waste is any substance discarded after primary use, or is worthless, defective and of no use. A by-product, by contrast is a joint product of relatively minor economic value. A waste product may become a by-product, joint product or resource through an invention that raises a waste product's value above zero.
Examples include municipal solid waste (household trash/refuse), hazardous waste, wastewater (such as sewage, which contains bodily wastes (feces and urine) and surface runoff), radioactive waste, and others.
A toilet is a piece of sanitary hardware that collects human waste (urine and feces) and sometimes toilet paper, usually for disposal. Flush toilets use water, while dry or non-flush toilets do not. They can be designed for a sitting position popular in Europe and North America with a toilet seat, with additional considerations for those with disabilities, or for a squatting posture more popular in Asia, known as a squat toilet. In urban areas, flush toilets are usually connected to a sewer system; in isolated areas, to a septic tank. The waste is known as blackwater and the combined effluent, including other sources, is sewage. Dry toilets are connected to a pit, removable container, composting chamber, or other storage and treatment device, including urine diversion with a urine-diverting toilet. "Toilet" or "toilets" is also widely used for rooms containing only one or more toilets and hand-basins. Lavatory is an older word for toilet.
The technology used for modern toilets varies. Toilets are commonly made of ceramic (porcelain), concrete, plastic, or wood. Newer toilet technologies include dual flushing, low flushing, toilet seat warming, self-cleaning, female urinals and waterless urinals. Japan is known for its toilet technology. Airplane toilets are specially designed to operate in the air. The need to maintain anal hygiene post-defecation is universally recognized and toilet paper (often held by a toilet roll holder), which may also be used to wipe the vulva after urination, is widely used (as well as bidets).
A urine-diverting dry toilet (UDDT) is a type of dry toilet with urine diversion that can be used to provide safe, affordable sanitation in a variety of contexts worldwide. The separate collection of feces and urine without any flush water has many advantages, such as odor-free operation and pathogen reduction by drying. While dried feces and urine harvested from UDDTs can be and routinely are used in agriculture (respectively, as a soil amendment and nutrient-rich fertilizer—this practice being known as reuse of excreta in agriculture), many UDDT installations do not apply any sort of recovery scheme. The UDDT is an example of a technology that can be used to achieve a sustainable sanitation system. This dry excreta management system (or "dry sanitation" system) is an alternative to pit latrines and flush toilets, especially where water is scarce, a connection to a sewer system and centralized wastewater treatment plant is not feasible or desired, fertilizer and soil conditioner are needed for agriculture, or groundwater pollution should be minimized.
There are several types of UDDTs: the single vault type which has only one feces vault; the double vault type which has two feces vaults that are used alternately; and the mobile or portable UDDTs, which are a variation of the single vault type and are commercially manufactured or homemade from simple materials. A UDDT can be configured as a sitting toilet (with a urine diversion pedestal or bench) or as a squatting toilet (with a urine diversion squatting pan). The most important design elements of the UDDT are: source separation of urine and feces; waterless operation; and ventilated vaults (also called "chambers") or removable containers for feces storage and treatment. If anal cleansing takes place with water (i.e., the users are "washers" rather than "wipers"), then this anal cleansing water must be drained separately and not be allowed to enter the feces vault.
A pit latrine, also known as pit toilet, is a type of toilet that collects human waste in a hole in the ground. Urine and feces enter the pit through a drop hole in the floor, which might be connected to a toilet seat or squatting pan for user comfort. Pit latrines can be built to function without water (dry toilet) or they can have a water seal (pour-flush pit latrine). When properly built and maintained, pit latrines can decrease the spread of disease by reducing the amount of human feces in the environment from open defecation. This decreases the transfer of pathogens between feces and food by flies. These pathogens are major causes of infectious diarrhea and intestinal worm infections. Infectious diarrhea resulted in about 700,000 deaths in children under five years old in 2011 and 250 million lost school days. Pit latrines are a low-cost method of separating feces from people.
A pit latrine generally consists of three major parts: a hole in the ground, a concrete slab or floor with a small hole, and a shelter. The shelter is also called an outhouse. The pit is typically at least three meters (10 ft) deep and one meter (3 ft) across. The hole in the slab should not be larger than 25 cm (10 in) to prevent children falling in. Light should be prevented from entering the pit to reduce access by flies. This may require the use of a lid to cover the hole in the floor when not in use. The World Health Organization recommends that pits be built a reasonable distance from the house, ideally balancing easy access against smell. The distance from water wells and surface water should be at least 10 m (30 ft) to decrease the risk of groundwater pollution. When the pit fills to within 0.5 m (1+1⁄2 ft) of the top, it should be either emptied or a new pit constructed and the shelter moved or re-built at the new location. Fecal sludge management involves emptying pits as well as transporting, treating and using the collected fecal sludge. If this is not carried out properly, water pollution and public health risks can occur.
Blackwater in a sanitation context denotes wastewater from toilets which likely contains pathogens that may spread by the fecal–oral route. Blackwater can contain feces, urine, water and toilet paper from flush toilets. Blackwater is distinguished from greywater, which comes from sinks, baths, washing machines, and other household appliances apart from toilets. Greywater results from washing food, clothing, dishes, as well as from showering or bathing.
Blackwater and greywater are kept separate in "ecological buildings", such as autonomous buildings. Recreational vehicles often have separate holding tanks for greywater from showers and sinks, and blackwater from the toilet.
Toilet paper, (also referred to as toilet/bath/bathroom tissue or toilet roll) is a tissue paper product primarily used to clean the anus and surrounding region of feces (after defecation), and to clean the external genitalia and perineal area of urine (after urination).
It is commonly supplied as a long strip of perforated paper wrapped around a cylindrical paperboard core, for storage in a dispenser within arm's reach of a toilet. The bundle, or roll of toilet paper, is specifically known as a toilet roll, loo roll, or bog roll (in Britain).