Toilet

A toilet is a sanitation fixture used primarily for the disposal of human urine and feces. They are often found in a small room referred to as a toilet/bathroom/lavatory. Flush toilets, which are common in many parts of the world, may be connected to a nearby septic tank or more commonly in urban areas via "large" (3 - 6 in) sewer pipe connected to a sewerage pipe system. The water and waste from many different sources is piped in large pipes to a more distant sewage treatment plant. Chemical toilets are used in mobile and many temporary situations where there is no access to sewerage, dry toilets, including pit toilets and composting toilet require no or little water with excreta being removed manually or composted in situ.

Ancient civilizations used toilets attached to simple flowing water sewage systems included those of the Indus Valley Civilization, e.g., Harappa and Mohenjo-daro which are located in present day India and Pakistan and also the Romans and Egyptians. Although a precursor to the modern flush toilet system was designed in 1596 by John Harington, such systems did not come into widespread use until the late nineteenth century. Thomas Crapper was one of the early makers of toilets in England.

Diseases, including cholera which still affects some 3 million people each year, can be largely prevented when effective sanitation and water treatment prevents fecal matter from contaminating waterways, groundwater and drinking water supplies. Infected water supplies can be treated to make the water safe for consumption and use. There have been five main cholera outbreaks and pandemics since 1825. In London alone, the second killed 14,137 people in 1849, and the third took 10,738 lives in 1853-54. In 1849 the English physician John Snow published a paper On the Mode of Communication of Cholera, in which he suggested that cholera might be water born. During the 1854 epidemic, he collected and analyzed data establishing that people who drank water from contaminated sources such as the Broad Street pump died of cholera at much higher rates than those who got water elsewhere.

According to The Global Water Supply and Sanitation Assessment 2000 by the World Health Organization, 40% of the global population does not have access to "good" "excreta disposal facilities"—they live mostly in Asia and Africa. There are efforts being made to design simple effective squat toilets for these people. Usually, they are made by digging a hole, then installing a premade plastic squat toilet seat atop this hole, covering the walls with canvas.

Ancient civilizations


According to Teresi et al. (2002):

"The third millennium BC was the 'Age of Cleanliness.' Toilets and sewers were invented in several parts of the world, and Mohenjo-Daro circa 2800 BC had some of the most advanced, with lavatories built into the outer walls of houses. These were primitive 'Western-style' toilets made from bricks with wooden seats on top. They had vertical chutes, through which waste fell into street drains or cesspits. Sir Mortimer Wheeler, the director general of archaeology in India from 1944 to 1948, wrote, 'The high quality of the sanitary arrangements could well be envied in many parts of the world today.'"

The toilets at Mohenjo-Daro, built about 2600 BC and described above, were only used by the affluent classes. Most people would have squatted over old pots set into the ground or used open pits. The people of the Harappan civilization in Pakistan and north-western India had primitive water-cleaning toilets that used flowing water in each house that were linked with drains covered with burnt clay bricks. The flowing water removed the human wastes.

Early toilets that used flowing water to remove the waste are also found at Skara Brae in Orkney, Scotland, which was occupied from about 3100 BC until 2500 BC. Some of the houses there have a drain running directly beneath them, and some of these had a cubicle over the drain. Around the 18th century BC, toilets started to appear in Minoan Crete; Egypt in the time of the Pharaohs and ancient Persia. In Roman civilization, toilets using flowing water were sometimes part of public bath houses.

In 2012, archaeologists founded what is believed to be Southeast Asia's earliest latrine during the excavation of a neolithic village in the Rạch Núi archaeological site, Southern Viet Nam. The toilet, dating back 1500 BC, yielded important clues about early Southeast Asian society. More than 30 preserved feces from humans and dogs containing fish and shattered animal bones from the site provided a wealth of information on both the diet of humans and dogs at Rạch Núi, but also on the types of parasites each had to contend with.

Roman toilets, like the ones pictured here, are commonly thought to have been used in the sitting position. But sitting toilets only came into general use in the mid-19th century in the Western world. The Roman toilets were probably elevated to raise them above open sewers which were periodically "flushed" with flowing water, rather than elevated for sitting. The Romans weren't the first civilisation to adopt a sewer system - The Indus Valley civilisation had a rudimentary network of sewers built under grid pattern streets and it was the most advanced seen so far. Squat toilets (also known as an Arabic, French, Chinese, Japanese, Korean, Iranian, Indian, Turkish or Natural-Position toilet) are toilets used by squatting rather than sitting, and are still used by the majority of the world's population. There are several types of squat toilets, but they all consist essentially of a hole in the ground or floor with various provisions for human waste.

Early modern Europe
Chamber pots were in common use in Europe from ancient times, even being taken to the Middle East by Christian pilgrims during the Middle Ages. By the Early Modern era, chamber pots were frequently made of china or copper and could include elaborate decoration. They were emptied into the gutter of the street nearest to the home. During the Victorian era, British housemaids emptied household chamber pots into a "slop sink" that was inside a housemaid's cupboard on the upper floor of the house. The housemaids' cupboard also contained a separate sink, made of wood with a lead lining to prevent chipping china chamber pots, for washing the "bedroom ware". Once indoor running water was built into British houses, servants were sometimes given their own lavatory downstairs, separate from the family lavatory.

By the 16th century, cesspits and cesspools were increasingly dug into the ground near houses in Europe as a means of collecting waste, as urban populations grew and street gutters became blocked with the larger volume of human waste. Rain was no longer sufficient to wash away waste from the gutters. A pipe connected the latrine to the cesspool, and sometimes a small amount of water washed waste through the pipe into the cesspool. Cesspools would be cleaned out by tradesmen, who pumped out liquid waste, then shovelled out the solid waste and collected it in horse-drawn carts during the night. This solid waste would be used as fertilizer. The perception that human waste had value as fertilizer, and in ammonia production, delayed the construction of a modern sewer system in Paris as a replacement for the city's cesspool system. In the early 19th century, public officials and public hygiene experts studied and debated the matter at length, for several decades. The construction of an underground network of pipes to carry away solid and liquid waste was only begun in the 1880s, gradually replacing the cesspool system, although cesspools were still in use in some parts of Paris into the 20th century. The growth of indoor plumbing, toilets and bathtubs with running water came at the same time.

America
American lavatories followed the pattern of constructing cesspools in urban areas, using the practise already established in Europe, although the use of the outhouse near the family home was also common where more land was available, and keeping the waste well away from the well water was not a challenge. A textbook of architecture from 1903 indicates that cesspool construction was ideally done with 20-inch thick quarried stone, with cement mortar, and 6 feet deep. The chain-pull indoor toilet, invented in England in the 1880s, was soon introduced to America, in the homes of the wealthy and in hotels. Flush toilets were introduced in the 1890s. Public awareness of germ theories about disease, as well as inexpensive manufacturing methods, helped the flushing toilet to spread to middle class and even working class households. Important American inventors who contributed to the development of the toilet during the early 1900s included William Elvis Sloan (1867-1961), of Chicago, Illinois, and Philip Haas (1875-1927), of Dayton, Ohio. Sloan introduced the 'Flushometer' and was responsible for several flush valve designs. Haas obtained numerous patents for flush valves, flushing systems, and water closet designs. Indoor plumbing, including flushing toilets, was common in American households by the 1920s. Edward and Clarence Scott began selling white perforated toilet tissue during this era, bringing additional convenience to the American public, who had until then relied on rough paper for toilet use.

Operation
A typical flush toilet is a vitreous, ceramic bowl containing water plus special plumbing made to be rapidly filled with more water. The water in the toilet bowl is connected to a hollow drain pipe shaped like an upside down U connecting the drain. One side of the U channel is arranged as a hollow siphon tube longer than the water in the bowl is high. The siphon tube connects to the drain. The bottom of the upside down U-shaped drain pipe limits the height of the water in the bowl before it flows down the drain. If water is poured slowly into the toilet bowl it simply flows over the bottom of the upside down U and pours slowly down the drain—the toilet does not flush. The water in the bowl both acts as a barrier to sewer gas entering and as a receptacle for waste. Sewer gas is vented through a vent pipe attached to the sewer line.

When a user flushes a toilet, a valve opens, and allows the toilet tank's water to quickly enter the toilet bowl. This rapid influx of water into the toilet bowl from the tank causes the swirling water in the bowl to rapidly rise and fill the upside down U-shaped drain and the siphon tube mounted in the back of the toilet. This full siphon tube starts the toilet's siphon action. The siphon action rapidly (4–7 seconds) “pulls” nearly all of the water and waste in the bowl and the on-rushing tank water down the drain—it flushes. When most of the water has drained out of the bowl, the continuous column of water up and over the bottom of the upside-down U-shaped drain pipe (the siphon) is broken when air enters the siphon tube. The toilet then gives its characteristic gurgle as the siphon action ceases and no more water flows out of the toilet. After flushing, the flapper valve in the water tank closes, and various water lines and valves connected to the household water supply refill the toilet tank and bowl. The toilet is again ready for use.

At the top of the toilet bowl is a rim built into the toilet with many slanted drain holes connected to the toilet tank to fill, rinse and induce swirling in the toilet bowl when it is flushed. Mounted above the toilet is a large holding tank with about (now) 1.6 to 1.2 USgal of water. This tank is built with a large drain 2.0 to 3.0 in diameter hole at its bottom covered by a flapper valve that allows the water to rapidly leave the holding tank. The toilet's plumbing is built to allow entry of the toilet tank’s water into the toilet in a very short period of time. This water pours through the holes in the rim and a siphon jet hole about 1.0 in diameter in the bottom of the toilet. Other toilets use a large hole in the front of the rim to allow rapid filling of the toilet bowl.

Manufacture
A two-piece attaching seat and toilet bowl lid are typically mounted over the toilet bowl, to allow covering the toilet when it is not in use, and to provide seating comfort while using the toilet. A toilet's body is made from vitreous china, which starts out as a thin clay mixture called a slip. It takes about 20 kg of slip per toilet.

This slip is poured into the space between plaster of Paris molds. Toilet bowl, toilet rim, toilet tank and toilet tank lid all require separate molds. The molds are assembled and set up for filling and the slip-filled molds sit for about an hour after filling while the plaster of Paris molds absorb moisture from the slip making it semisolid next to the mold but staying liquid further from the surface of the molds. Then, the workers remove plugs that allow any excess liquid slip from the centers of the mold to pour from the mold—this excess slip is recycled for later use. This drained-out slip leaves voids inside the fixture using less material, keeping it both lighter and easier to fire in a kiln, and it allows the formation of intricate waste lines in the fixture—the drain's centers are poured out as slip.

At this point, the toilet parts without their molds look like and are about as strong as soft clay. After about one hour the top core mold (interior of toilet) is removed. The rim mold bottom, which includes a place to mount the holding tank is removed, and it has the appropriate slanted holes for the rinsing jets cut and the mounting holes for tank and seat are punched into the rim piece. Large flapper valve holes for rapid water entry into the toilet are cut into the rim pieces. The exposed top of the bowl piece is then covered with a thick slip and the still uncured rim piece is attached on top of the bowl piece. The bowl and hollow rim are now a single piece. The bowl plus rim is then inverted and the toilet bowl is set upside down on the top rim mold to hold the pieces together as they dry. Later all the rest of the mold pieces are removed. As the clay dries further it hardens more and continues to shrink. After a few hours the casting is self-supporting, and is called greenware.

After the molds are removed' workers use hand tools and sponges to smooth the edges and surface of the greenware and remove the mold joints or roughness: this is called fettling. For large scale production pieces these steps may be automated. The parts are then left outside or put in a warm dry room to dry before going through a dryer at about 93°C (200°F), for about 20–36 hours.

After finishing the surfaces, the bowls and tanks are sprayed with glaze of various kinds to get different colors. This glaze is designed to shrink and contract at the same rate as the greenware while undergoing firing. After being sprayed with glaze the toilet bowls, tanks, and lids are placed in stacks on a conveyor belt or "car" that slowly goes through a large kiln to be fired. The belt slowly moves the glaze covered greenware into a tunnel kiln, which has different temperature zones inside it starting at about 200°C (400°F) at the front, increasing towards the middle to over 1,200°C (2,200°F) degrees and exiting around out 90°C (200°F). During the firing in the kiln, the greenware and glaze are vitrified as one solid finished unit. Transiting the kiln takes glaze covered greenware around 23–40 hours.

When the pieces are removed from the kiln and fully cooled, they are ready for inspection for cracks. After inspection, the flushing mechanism may be installed on a one piece toilet. On a two piece toilet with a separate tank the flushing mechanism may only be put on the tank with final assembly waiting installation. The seat too may be installed at this time, or the parts may be sold separately and assembled by a plumbing distributor.

Water usage
Various forms of flush toilets have become widely used in modern times The amount of water used by modern toilets is a significant portion of personal water usage, totaling as much as about 90 liters of water per capita per day.

When a toilet is flushed, the water flows into a sewage system and eventually ends in a water treatment plant. Here the water is cleaned, sanitized and possibly re-used.

Modern low flush toilet designs allow the use of much less water per flush—1.6 to 1.2 USgal per flush—but may require the sewage treatment system be modified for the more concentrated waste. Dual flush toilet allow the use to select between a flush for urine or feces saving a significant amount of water over conventional units. You push the flush handle up for one kind of flush and down for the other. In some places users are encouraged not to flush after urination. Flush toilets, if plumbed for it, may also use greywater (water previously used for washing dishes, laundry and bathing) for flushing rather than potable water (drinking water). Some modern toilets pressurize the water in the tank which initiates flushing action with less water usage. Heads (on ships) are typically flushed with seawater.

Pit toilets
A pit toilet is a dry toilet system which collects human excrement and urine in a large container or trench and ranges from a simple slit trench dug in the ground to more elaborate systems with seating and ventilation systems. They are more often used in emergency, rural and wilderness areas as well as in much of the developing world. The waste pit or trench, in some cases, will be large enough that the reduction in mass of the contained waste products by the ongoing process of decomposition allows the pit to be used more or less permanently. In other cases, when the pit becomes too full, it may be emptied or the hole covered with dirt. Pit toilets have to be located away from drinking water sources (wells, streams, etc.) to minimize the possibility of disease spread. Army units typically use a form of pit toilet when they are in the field and away from functional sewerage systems. The use of correctly located pit toilets were found to prevent much of the spread of various diseases which used to kill many more soldiers than the bullets and artillery used in pre-1940 warfare.

Dry toilets
Dry toilets, which use very limited or no water for flushing include the pit toilet (a simple hole in the ground, or one with ventilation, fly guards and other improvements), the composting toilet (which mixes excrement with carbon rich materials for faster decomposition), the incinerating toilet (which burns the excrement), and the tree bog (a simple system for converting excrement to direct fertiliser for trees). The pig toilet from the Indian state of Goa which consists of an outhouse linked to a pig enclosure by a chute is still in use to a limited extent but the subsequent use of the pigs for food carries a significant risk for human health.

The unsanitary 'flying toilet' used in African slums where plastic shopping bags are first used as a container for excrement and are then thrown as far away as possible." This practice has led to the banning of the manufacture and import of such bags in Uganda, Kenya, and Tanzania.

A toilet that pays its users has been opened in Musiri, Tamil Nadu, India. It is the first of its kind. The feces it receives are composted, and the urine is used as fertilzer for bananas and other food crops. Users are paid up to the equivalent of 12 US cents a month.

Before the introduction of modern flush toilets it was common for people to use a chamber pot at night and then to dispose of the 'nightsoil' in the morning; this practice (known as slopping out) continued in prisons in the United Kingdom until recently and is still in use in the Republic of Ireland. The garderobe was used in medieval times, and replaced by the privy midden and pail closet in early industrial Europe.

UD toilet, UDD toilet, and UDDT system
These toilets have two compartments. One for urine diversion and one for the feces. A urine diversion toilet, UD toilet or UDT, flushes one or both compartments with water. A urine diversion dry toilet, UDD toilet, or UDDT is more similar to a dry toilet. The term UDDT can also refer to a system incorporating a UD or UDD toilet to recover water or utilize wastes as a fertilizer or biofuel. Astronauts use a UDDT to recover potable water in the space station.

Chemical toilets
Chemical toilets which do not require a connection to a water supply are used in a variety of situations. Examples include passenger train toilets and airplane toilets and also complicated space toilets for use in zero-gravity spacecraft.

Public toilets
A public toilet, frequently called a restroom, is accessible to the general public. It may be within a building that, while privately owned, allows public access. Access to a public toilet may require a fee, (pay toilet), or may be limited to business's customers.

Depending on culture, there may be varying degrees of separation between men and women and different levels of privacy. Typically, the entire room, or a stall or cubicle containing a toilet is lockable. Urinals, if present in a men's toilet, are typically mounted on wall with or without a divider between them. In the most basic form, a public toilet may be not much more than an open latrine. Another form is a street urinal known as a pissoir after the French term (see Urinal).

In more luxurious variations there may be an attendant, towels, showers, etc. A fairly common feature in more modern toilets is an area to change baby diapers.

A charge levied in the UK during the mid-20th century was one British penny, hence the generally adopted term "spend a penny" meaning to use the toilet.

Portable toilets
The portable toilet is used on construction sites and at large outdoor gatherings where there are no other facilities. They are typically self-contained units that are made to be easily moved to different locations as needed. Most portable toilets are unisex single units with privacy ensured by a simple lock on the door. The units are usually light weight and easily transported by a flatbed truck and loaded and unloaded by a small forklift. Many portable toilets are small molded plastic or fiberglass portable rooms with a lockable door and a receptacle to catch waste in a chemically treated container. If used for an extended period of time they have to be cleaned out and new chemicals put in the waste receptacle. For servicing multiple portable toilets tanker trucks, often called "Honey Trucks", are equipped with lage vacuums to evacuate the waste and replace the chemicals.

High-tech toilets
"High-tech" toilets include features such as: automatic-flushing mechanisms that flush a toilet or urinal when finished; water jets, or "bottom washers" like a bidet; blow dryers; artificial flush sounds to mask noises; and urine and stool analysis for medical monitoring. Matsushita's "Smart Toilet" checks blood pressure, temperature, and blood sugar. Some feature automatic lid operation, heated seats, deodorizing fans or automated paper toilet-seat-cover replacers. Interactive urinals have been developed in several countries, allowing users to play video games as with the "Toylet", produced by Sega, that uses pressure sensors to detect the flow of urine and translates it into on-screen action.

Floating toilets
A floating toilet is essentially an outhouse built on a platform built above or floating on the water. Instead of wastes going into the ground they are collected in a tank or barrel. To reduce the amount of waste that needs to hauled to shore, many use urine diversion. It was developed for residents without quick access to land or connection to a sewer systems. It is also used in areas subjected to prolonged flooding. The need for this type of toilet is high in areas like Cambodia where the World Bank cited in 2008 that nearly 10,000 people died as a result of poor sanitation.

Chamber pots
A chamber pot is a receptacle in which one would excrete waste in a ceramic or metal pot. Among Romans and Greeks, chamber pots were brought to meals and drinking sessions. Johan J. Mattelaer said, “Plinius has described how there were large receptacles in the streets of cities such as Rome and Pompeii into which chamber pots of urine were emptied. The urine was then collected by fullers.” This method was used for hundreds of years; shapes, sizes, and decorative variations changed throughout the centuries. This method is no longer used in developed countries, with the exception of hospital bedpans.

Garderobes
Garderobes were toilets used in the Middle Ages, most commonly found in upper-class dwellings. Essentially, they were flat pieces of wood or stone spanning from one wall to the other, with one or more holes to sit on. These would go into pipes that would lead outside the castle or manor. Garderobes would be placed in areas away from bedrooms to shun the smell and also near kitchens or fireplaces to keep the enclosure warm.

Urinals
Although it is possible for urinals to be used by females, they were originally designed for males. They are intended for the disposal of liquid waste, not solid waste. Urinals are meant to be used for the convenience of male users in a standing position. They typically have no door or stall enclosure, and thus take up less space. These fixtures are most commonly found in public places, but can occasionally be found in a private home

Squat toilets
The squat toilet (also called “squatter” or “squatty-potty”) consists of a hole in the ground. However, common modern versions flush like a modern seated toilet, and are not to be compared to a contemporary portable toilet with no plumbing. To use this toilet, one is in a squatting position rather than sitting, by placing one foot on each side of the toilet and squatting over it. Modern versions are in separate stalls when they are in public lavatories, and include toilet tissue rolls for the user's convenience. The squatting method is accompanied by advantages as well health benefits that connect to easiness of procedures such as child birth. The squat toilet is most commonly found in Asia, Africa, and the Middle East but can also occasionally be found in some European (Romania), Mediterranean, and South American countries.

Toilet
The word toilet came to be used in English along with other French fashions. It originally referred to the toile, French for "cloth", draped over a lady or gentleman's shoulders while their hair was being dressed, and then (in both French and English) by extension to the various elements, and also the whole complex of operations of hairdressing and body care that centered at a dressing table, also covered by a cloth, on which stood a mirror and various brushes and containers for powder and make-up: this ensemble was also a toilette, as also was the period spent at the table, during which close friends or tradesmen were often received. The English poet Alexander Pope in The Rape of the Lock (1717) described the intricacies of a lady's preparation.

The word toilet may also be used, especially in British English to describe the room containing the fixture, for which euphemisms such as restroom or bathroom are used in American English. Prior to the introduction of modern flush toilets, most human waste disposal was done through the use of household chamber pots, or took place outdoors in outhouses or latrines. Pail closets were introduced in England and France in an attempt to reduce sewage problems in rapidly expanding cities.

And now, unveil'd, the toilet stands display'd Each silver vase in mystic order laid.

These various senses are first recorded by the OED in rapid sequence in the later 17th century: the set of "articles required or used in dressing" 1662, the "action or process of dressing" 1681, the cloth on the table 1682, the cloth round the shoulders 1684, the table itself 1695, and the "reception of visitors by a lady during the concluding stages of her toilet" 1703 (also known as a "toilet-call"), but in the sense of a special room the earliest use is 1819, and this does not seem to include a lavatory.

Through the 18th century, everywhere in the English-speaking world, these various uses centred around a lady's draped dressing-table remained dominant. In the 19th century, apparently first in the United States, the word was adapted as a genteel euphemism for the room and the object as we know them now, perhaps following the French usage cabinet de toilette, much as powder-room may be coyly used today, and this has been linked to the introduction of public toilets, for example on railway trains, which required a plaque on the door. The original usages have become obsolete, and the table has become a dressing-table.

Vestiges of the original meaning continue to be reflected in terms such as toiletries, eau de toilette and toiletry bag (to carry flannels, soaps, etc.). This seemingly contradictory terminology has served as the basis for various parodies e.g. Cosmopolitan magazine ("If it doesn't say 'eau de toilette' on the label, it most likely doesn't come from the famed region of Eau de Toilette in France and might not even come from toilets at all.")

The word toilet itself may be considered an impolite word in Anglophone North America, while elsewhere the word is used without any embarrassment. The choice of the word used instead of toilet is highly variable, not just by regional dialect but also, at least in Britain, by class connotations. Nancy Mitford wrote an essay out of the choice of wording; see U and non-U English. Some manufacturers show this uneasiness with the word and its class attributes: American Standard, the largest manufacturer, sells them as "toilets", yet the higher priced products of the Kohler Company, often installed in more expensive housing, are sold as commodes or closets, words which also carry other meanings. Confusingly, products imported from Japan such as TOTO are referred to as "toilets", even though they carry the cachet of higher cost and quality. When referring to the room or the actual piece of equipment, the word toilet is often substituted with other euphemisms and dysphemisms (See toilet humor).

As old euphemisms have become accepted, they have been progressively replaced by newer ones, an example of the euphemism treadmill at work. The choice of word used to describe the room or the piece of plumbing relies as much on regional variation (dialect) as on social situation and level of formality (register).

Lavatory
The term lavatory, abbreviated in slang to lav, derives from the lavātōrium, which in turn comes from Latin lavō ("I wash"). The word was originally used to refer to a vessel for washing, such as a sink/wash basin, but eventually came to mean a room with such washing vessels, as for example in medieval monasteries, where the lavatorium was the monks' communal washing area. The toilets in monasteries however were not in the lavatorium but in the reredorter. Nevertheless the word was later associated with toilets and the meaning evolved into its current one, namely a polite and formal euphemism for a toilet and the room containing it. Lavatory is the common signage for toilets on commercial airlines around the world, see Aircraft lavatory.

Loo
The origin of the (chiefly British) term loo is unknown. According to the OED, the etymology is obscure, but it might derive from the word Waterloo. The first recorded entry is in fact from James Joyce's Ulysses (1922)'': "O yes, mon loup. How much cost? Waterloo. Watercloset".

Other theories are:
 * That it derives from the term "gardyloo" (a corruption of the French phrase gardez l'eau! (or maybe ) loosely translated as "watch out for the water!") which was used in medieval times when chamber pots were emptied from a window onto the street. However the first recorded usage of "loo" comes long after this term became obsolete.
 * That the word comes from nautical terminology, loo being an old-fashioned word for lee. The standard nautical pronunciation (in British English) of leeward is looward. Early ships were not fitted with toilets but the crew would urinate over the side of the vessel. However it was important to use the leeward side. Using the windward side would result in the urine blown back on board: hence the phrases 'pissing into the wind' and 'spitting into the wind'. Even now most yachtsmen refer to the loo rather than the heads.
 * That the word derives from the 17th century preacher Louis Bourdaloue. Bourdaloue's sermons at the Saint Paul-Saint Louis Church in Paris lasted at least three hours and myth has it that wealthier ladies took along "travelling" chamber pots that could be hidden under their dresses whenever the need arose to avoid the need to leave. Due to the popularity of the myth the bowls became known as Bourdaloues after the preacher and the name became corrupted to portaloos and sometimes just plain loos due to the habit of shortening words in slang.
 * That the word comes from the French word lieu (place), as in lieu d'aisance (literally: "place of ease", a common euphemism for lavatory) or lieu à l'anglaise (literally: "English place"). From around 1770 the term lieu à l'anglaise began to appear in France, referring to this English invention which was sometimes installed for the benefit of English visitors. (Ashenburg p. 138)

WC
The WC refers to the initial letters of Water Closet, which, despite being an English language abbreviation, is not in common use in English-speaking countries – but is widely used internationally: in France (pronounced "le vay-say" or "le vater"), in Italy (pronounced "vi-ci" or "vater"), Romania (pronounced "veh-cheu"), the Netherlands (pronounced "waysay"), Germany, Switzerland and Hungary (pronounced "ve-tse"), Denmark (pronounced "ve-se"), Norway (pronounced "vay-say"), Poland (pronounced "vu-tse"), Spain (pronounced "uve-cé" or "váter"), China, and others.

Other
Lexicographer Eric Partridge derives khazi, also spelt karzy, kharsie or carzey, from a low Cockney word carsey originating in the late 19th century and meaning a privy. Carsey also referred to a den or brothel. It is presumably derived from the Italian casa for house, with the spelling influenced by its similar sound to khaki. Khazi is now most commonly used in the city of Liverpool in the UK, away from its cockney slang roots. An alternative derivation is from Christopher Chippindale, who states that khazi derives from Army slang used by expatriate officers of the British Empire who took a dislike to the habits of, and steaming rain forest inhabited by, the Khasi people of the Khasia hills on the northern frontier of India.

The Dunny is an Australian expression for an outside toilet or outhouse. The person who appeared weekly to empty the pan beneath the seat was known as the "dunnyman". The word derives from the British dialect word dunnekin, meaning "dung-house". It is now an informal word used for any lavatory and is most often used referring to drop or pit lavatories in the Australian bush, which are also called thunderboxes.

The Privy is an old fashioned term used more in the North of England and in Scotland; "privy" is an old alternative for "private", as in Privy council. It is used interchangeably in North America for various terms for the outhouse.

The netty is the most common word used in North East England. Many outsiders are often bemused when a Geordie or a Mackem states they are "gannin te the netty" (going to the bathroom). The etymology of the word is uncertain, but it is believed to be either derived from a corruption of "necessity" or from graffiti scrawled on Hadrian's Wall. It is linked to the Italian word gabinetti meaning "toilets" (singular gabinetto).

Latrine is a term common in the military, specifically for the Army and Air Force for any point of entry facility where human waste is disposed of, which a civilian might call a bathroom or toilet, regardless of how modern or primitive it is. Traditionally the Royal Navy along with the United States Navy and Marine Corps use the nautical term "Head" to describe the same type of facility, regardless of whether it is located on a ship or on the land.

The Jacks is Irish slang for toilet. It perhaps derives from "jakes", an old English term.

The standalone toilet enclosure has been variously known as a "back house", "house of ease", "house of office", "little house", or "outhouse". The house of office was a common name for a toilet in seventeenth century England, used by, among others, Samuel Pepys on numerous occasions: October 23, 1660: ...going down into my cellar..., I put my foot into a great heap of turds, by which I find Mr Turner's house of office is full and comes into my cellar.

In the Philippines the abbreviation CR (Comfort Room) is commonly used.

Culture
There are many different ways to clean oneself after using the toilet, depending on national mores and local resources. An important part of early childhood education is toilet training.

In the Western world, the most common method of cleaning after using a toilet is by toilet paper or by using a bidet, which has been increasing in popularity. In the Middle East and some countries in Asia, and South Asian countries such as India and Pakistan, the custom is to use water, either with or without toilet paper. Traditionally, the left hand is used for this, for which reason that hand is considered impolite or polluted in many Eastern countries. The Islamic faith has a particular code, Qaḍāʼ al-Ḥājah describing Islamic toilet etiquette.

Toilet humour is a name given to a type of off-colour humour dealing with defecation, urination, and flatulence.