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A flush toilet (also known as a flushing toilet, water closet (WC) – see also toilet names) is a
toilet A toilet is a piece of sanitary hardware that collects human 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 popu ...
that disposes of
human waste Human waste (or human excreta) refers to the waste products of the human digestive system, menses, and human metabolism including urine and faeces. As part of a sanitation system that is in place, human waste is collected, transported, treate ...
(principally
urine Urine is a liquid by-product of metabolism in humans and in many other animals. Urine flows from the kidneys through the ureters to the urinary bladder. Urination results in urine being excreted from the body through the urethra. Cellul ...
and
feces Feces ( or faeces), known colloquially and in slang as poo and poop, are the solid or semi-solid remains of food that was not digested in the small intestine, and has been broken down by bacteria in the large intestine. Feces contain a rela ...
) by using the force of water to ''flush'' it through a drainpipe to another location for treatment, either nearby or at a communal facility, thus maintaining a separation between humans and their waste. Flush toilets can be designed for sitting (in which case they are also called "Western" toilets) or for squatting, in the case of squat toilets. Most modern sewage treatment systems are also designed to process specially designed ''
toilet paper Toilet paper (sometimes called toilet tissue or bathroom tissue) is a tissue paper product primarily used to clean the anus and surrounding anal region of feces after defecation, and to clean the perineal area and external genitalia of ur ...
''. The opposite of a flush toilet is a
dry toilet A dry toilet (or non-flush toilet, no flush toilet or toilet without a flush) is a toilet which, unlike a flush toilet, does not use flush water. Dry toilets do not use water to move excreta along or block odors. They do not produce sewage, and ...
, which uses no water for flushing. Flush toilets are a type of plumbing fixture and usually incorporate an "S", "U", "J", or "P" shaped bend called a trap that causes water to collect in the toilet bowl to hold the waste and act as a seal against noxious
sewer gas Sewer gas is a complex, generally obnoxious smelling mixture of toxic and nontoxic gases produced and collected in sewage systems by the decomposition of organic household or industrial wastes, typical components of sewage. Sewer gases may inclu ...
es. Most flush toilets are connected to a
sewerage Sewerage (or sewage system) is the infrastructure that conveys sewage or surface runoff (stormwater, meltwater, rainwater) using sewers. It encompasses components such as receiving drainage, drains, manholes, pumping stations, storm overflows, a ...
system that conveys
wastewater Wastewater is water generated after the use of freshwater, raw water, drinking water or saline water in a variety of deliberate applications or processes. Another definition of wastewater is "Used water from any combination of domestic, industrial ...
to a
sewage treatment plant Sewage treatment (or domestic wastewater treatment, municipal wastewater treatment) is a type of wastewater treatment which aims to remove contaminants from sewage to produce an effluent that is suitable for discharge to the surrounding en ...
; alternatively, a
septic tank A septic tank is an underground chamber made of concrete, fiberglass, or plastic through which domestic wastewater ( sewage) flows for basic sewage treatment. Settling and anaerobic digestion processes reduce solids and organics, but the treatm ...
or composting system may be used. Associated devices are
urinal A urinal (, ) is a sanitary plumbing fixture for urination only. Urinals are often provided in public toilets for male users in Western countries (less so in Muslim countries). They are usually used in a standing position. Urinals can be ...
s, which dispose of male urine, and bidets, which use water to cleanse the
anus The anus (Latin, 'ring' or 'circle') is an opening at the opposite end of an animal's digestive tract from the mouth. Its function is to control the expulsion of feces, the residual semi-solid waste that remains after food digestion, which, ...
,
perineum The perineum in humans is the space between the anus and scrotum in the male, or between the anus and the vulva in the female. The perineum is the region of the body between the pubic symphysis (pubic arch) and the coccyx (tail bone), includi ...
, and genitals after using the toilet.


Operation

A typical flush toilet is a fixed, vitreous
ceramic A ceramic is any of the various hard, brittle, heat-resistant and corrosion-resistant materials made by shaping and then firing an inorganic, nonmetallic material, such as clay, at a high temperature. Common examples are earthenware, porcelain, ...
bowl (also known as a pan) which is connected to a drain. After use, the bowl is emptied and cleaned by the rapid flow of water into the bowl. This flush may flow from a dedicated tank (cistern), a high-pressure water pipe controlled by a flush valve, or by manually pouring water into the bowl. Tanks and valves are normally operated by the user, by pressing a button, pushing down on a handle, pulling a lever or pulling a chain. The water is directed around the bowl by a molded flushing rim around the top of the bowl or by one or more jets, so that the entire internal surface of the bowl is rinsed with water.


Mechanical flush from a cistern

A typical toilet has a tank fixed above the bowl which contains a fixed volume of water, and two devices. The first device allows part of the contents of the tank (usually in the 3–6 liters; to 1 gallon range) to be discharged rapidly into the toilet bowl, causing the contents of the bowl to be swept or sucked out of the toilet and into the drain, when the user operates the flush. The second device automatically allows water to enter the tank until the water level is appropriate for a flush. The water may be discharged through a "toilet flapper valve" (not to be confused with a type of
check valve A check valve, non-return valve, reflux valve, retention valve, foot valve, or one-way valve is a valve that normally allows fluid ( liquid or gas) to flow through it in only one direction. Check valves are two-port valves, meaning they have ...
), or through a
siphon A siphon (from grc, σίφων, síphōn, "pipe, tube", also spelled nonetymologically syphon) is any of a wide variety of devices that involve the flow of liquids through tubes. In a narrower sense, the word refers particularly to a tube in a ...
. A float usually commands the refilling device.


Mechanical flush from a high-pressure water supply

Toilets without cisterns are often flushed through a simple flush valve or "Flushometer" connected directly to the water supply. These are designed to rapidly discharge a limited volume of water when the lever or button is pressed then released.


Manual flush (pour flush)

A toilet does not need be connected to a water supply, but may be pour-flushed. This type of flush toilet has no cistern or permanent water supply, but is flushed by pouring in a few litres of water from a container. The flushing can use as little as 2–3 litres ( to gallon). This type of toilet is common in many Asian countries. The toilet can be connected to one or two pits, in which case it is called a "pour flush pit latrine" or a "twin pit pour flush pit latrine". It can also be connected to a
septic tank A septic tank is an underground chamber made of concrete, fiberglass, or plastic through which domestic wastewater ( sewage) flows for basic sewage treatment. Settling and anaerobic digestion processes reduce solids and organics, but the treatm ...
.


Vacuum toilet

A vacuum toilet is a flush toilet that is connected to a vacuum sewer system, and removes waste by suction. They may use very little water (less than a quarter of a liter per flush) or none, (as in waterless urinals). Some flush with coloured disinfectant solution rather than with water. They may be used to separate blackwater and
greywater Greywater (or grey water, sullage, also spelled gray water in the United States) refers to domestic wastewater generated in households or office buildings from streams without fecal contamination, i.e., all streams except for the wastewater fro ...
, and process them separately (for instance, the fairly dry blackwater can be used for biogas production, or in a
composting toilet A composting toilet is a type of dry toilet that treats human waste by a biological process called composting. This process leads to the decomposition of organic matter and turns human waste into compost-like material. Composting is carried out b ...
). Passenger train toilets, aircraft lavatories, bus toilets, and ships with plumbing often use vacuum toilets. The lower water usage saves weight and avoids water slopping out of the toilet bowl in motion. Aboard vehicles, a portable collection chamber is used; if it is filled by positive pressure from an intermediate vacuum chamber, it need not be kept under vacuum.


Flushing systems

The flushing system provides a large flow of water into the bowl. They normally take the form of either fixed tanks of water or flush valves.


Flush tanks

Flush tanks or cisterns usually incorporate a mechanism to release water from the tank and an automatic valve to allow the cistern to be refilled automatically. This system is suitable for locations plumbed with or water pipes which cannot supply water quickly enough to flush the toilet; the tank is needed to supply a large volume of water in a short time. The tank typically collects between of water over a period of time. In modern installations the storage tank is usually mounted directly above and behind the bowl. Older installations, known as "high suite combinations", used a high-level cistern (tank), fitted above head height, activated by a pull chain connected to a flush lever on the cistern. When more modern close-coupled cistern and bowl combinations were first introduced, these were first referred to as "low suite combinations". Modern versions have a neater-looking low-level cistern with a lever that the user can reach directly, or a close-coupled cistern that is even lower down and fixed directly to the bowl. In recent decades the close coupled tank/bowl combination has become the most popular residential system, as it has been found by ceramic engineers that improved waterway design is a more effective way to enhance the bowl's flushing action than high tank mounting.


Tank fill valve

Tank fill valves are found in all tank-style toilets. The valves are of two main designs: the side-float design and the concentric-float design. The side-float design has existed for over a hundred years. The concentric design has only existed since 1957 but is gradually becoming more popular than the side-float design. The side-float design uses a float on the end of a lever to control the fill valve. The float is usually shaped like a ball, so the mechanism is often called a ball-valve or a
ballcock A ballcock (also balltap or float valve) is a mechanism or machine for filling water tanks, such as those found in flush toilets, while avoiding overflow and (in the event of low water pressure) backflow. The modern ballcock was invented by J ...
(cock in this context is an alternative term for valve; see, for example,
stopcock A stopcock is a form of valve used to control the flow of a liquid or gas. The term is not precise and is applied to many different types of valve. The only consistent attribute is that the valve is designed to completely stop the flow when cl ...
). The float was originally made from copper sheet, but it is now usually plastic. The float is located to one side of the main valve tower or inlet at the end of a rod or arm. As the float rises, so does the float-arm. The arm connects to the fill valve that blocks the water flow into the toilet tank and shuts off the water when the float reaches a set height. This maintains a constant level in the tank. The newer concentric-float fill valve consists of a tower which is encircled by a plastic float assembly. Operation is otherwise the same as a side-float fill valve, even though the float position is somewhat different. By virtue of its more compact layout, interference between the float and other obstacles (tank insulation, flush valve, and so on) is greatly reduced, thus increasing reliability. The concentric-float fill valve is also designed to signal to users automatically when there is a leak in the tank, by making much more noise when a leak is present than the older style side-float fill valve, which tends to be nearly silent when a slow leak is present. Newer fill valves have a delayed action that will not start filling the tank/cistern until the flapper/drop valve has closed which saves some water.


Flapper-flush valve or drop valve

In tanks using a flapper-flush valve, the outlet at the bottom of the tank is covered by a buoyant (plastic or rubber) cover, or flapper, which is held in place against a fitting (the ''flush valve seat'') by water pressure. The user pushes a lever to flush the toilet, which lifts the flush valve from the valve seat. The valve then floats clear of the seat, allowing the tank to empty quickly into the bowl. As the water level drops, the floating flush valve descends back to the bottom of the tank and covers the outlet pipe again. This system is common in homes in North America and in continental Europe. From 2001, due to a change in regulations, this flush system has also become available in the UK, where prior to that the siphon-type flush was mandated. Dual flush versions of this design with push buttons are widely available. They have one level of water for liquid waste and a higher level for
solid waste Municipal solid waste (MSW), commonly known as trash or garbage in the United States and rubbish in Britain, is a waste type consisting of everyday items that are discarded by the public. "Garbage" can also refer specifically to food waste, ...
. In North America, newer toilets have a flapper-flush valve. Older toilets have a flapper-flush valve. The larger flapper-flush valve is used on toilets that use less water, such as per flush. Some have a bell inlet for a faster more effective flush. A problem with the valve type flush mechanism is that it invariably starts to leak after a couple of years use due to wear and tear of the valve, particles, etc. trapped in the valve. Quite often this leakage is barely noticeable but adds up to a considerable water wastage. In the UK it has been found that between 5 and 8% of toilets (mostly dual flush drop valves) are leaking, each one between 215 and 400 litres (50 to 90 gallons) on average per day. Whilst they save more water than they leak, regular maintenance or use of a non-leaking flush mechanism will maximise water savings.


Siphon-flush mechanism

This system, invented by Albert Giblin and common in the UK, uses a storage tank similar to that used in the flapper-flush-valve system above. This flush valve system is sometimes referred to as a ''valveless'' system, since no valve as such is required. The siphon is formed of a vertical pipe that links the flush pipe to a domed chamber inside the cistern. A perforated disc, covered by a flexible plate or flap, is fitted inside this chamber and is joined by a rod to the flush lever. Pressing the lever raises the disc, forces water over the top of the siphon into the vertical pipe, and starts the siphonic flow. Water flows through the perforated disc past the flap until the cistern is empty, at which point air enters the siphon and the flush stops. The advantage of a siphon over the flush valve is that it has no sealing washers that can wear out and cause leaks, whereas other valve types - flapper, drop valve do leak, invariably after a couple of years of use and they have reduced water savings due to the valves not being maintained in practice. The siphon membrane will require occasional replacement. Until 1 January 2001, the use of siphon-type cisterns was mandatory in the UK but after that date the regulations additionally allowed pressure flushing cisterns and pressure flushing valves (though the latter remained forbidden in houses). Siphons can sometimes be more difficult to operate than a "flapper"-based flush valve because moving the lever requires more torque than a flapper system. This additional torque is required because a certain amount of water must be lifted up into the siphon passageway in order to initiate the siphon action in the tank. Splitting or jamming of the flexible flap covering the perforated disc can cause the cistern to go out of order. Dual-flush versions of the siphon cistern provide a shorter flush option by allowing air into the siphon to stop the siphon action before the tank is empty. The siphon system can also be combined with an air box to allow multiple siphons to be installed in a single trough cistern.


High-pressure or pressure-assisted tanks

Pressure-assisted toilets are sometimes found in both private (single, multiple, and lodging) installations as well as light commercial installations (such as offices). Products from several companies use to per flush. The mechanism consists of a plastic tank hidden inside the typical ceramic cistern or an exposed metal tank/cistern. When the tank fills with water, the air trapped inside compresses. When the air pressure inside the plastic tank reaches a certain level, the tank stops filling with water. A high-pressure valve located in the center of the vessel holds the air and water inside until the user flushes the toilet. During flushing, the user activates the valve via a button or lever, which releases the pressurized water into the bowl at a flow rate much higher than a conventional gravity-flow toilet. One advantage to this is lower water consumption than a gravity-flow toilet, or more effectiveness with a similar amount of water. As a result, the toilet does not clog as easily as those using non-pressurized mechanisms. However, there are some financial and safety disadvantages. These toilets are generally more expensive to purchase, and the plastic tanks need to be replaced about every 10 years. They also have a noisier flush than other models. In addition, pressure-assisted tanks have been known to explode, causing serious injuries and property damage, resulting in a massive recall beginning in 2012 of over 1.4 million toilets equipped with the tank. Some newer toilets use similar pressure-assist technology, along with a bowl and trapway designed to enhance the siphon effect; they use only per flush, or / for dual flush models. This design is also much quieter than other pressure-assist or flushometer toilets.


Tipping bucket type valve

A number of tipping bucket type cisterns have been developed. In the cistern is placed a tipping bucket with its axis aligned or perpendicular with the cistern. They have a lever which is rotated emptying the bucket which allows a variable flush. Usually the quantity of water is marked on the cistern and depending on the performance of the bowl a dual flush can be achieved e.g. 3/6, 3/4.5, 3/3, 1/2 litres, etc. A normal or delayed action refill valve is used.


Tankless style with high-pressure (flushometer) valve

In 1906,
William Sloan William is a male given name of Germanic languages, Germanic origin.Hanks, Hardcastle and Hodges, ''Oxford Dictionary of First Names'', Oxford University Press, 2nd edition, , p. 276. It became very popular in the English language after the Norm ...
first made available his "flushometer" style toilet flush valve, incorporating his patented design. The design proved to be very popular and efficient and remains so to this day. Flushometer toilet flush valves are still often installed in commercial restrooms, and are frequently used for both toilets and urinals. Since they have no tank, they have no fill delay and can be used again immediately. They can be easily identified by their distinctive chrome pipe-work, and by the absence of a toilet tank or cistern, wherever they are employed. Some flushometer models require the user to either depress a lever or press a button, which in turn opens a flush
valve A valve is a device or natural object that regulates, directs or controls the flow of a fluid (gases, liquids, fluidized solids, or slurries) by opening, closing, or partially obstructing various passageways. Valves are technically fitting ...
allowing mains-pressure water to flow directly into the toilet bowl or urinal. Other flushometer models are electronically triggered, using an infrared sensor to initiate the flushing process. Typically, on electronically triggered models, an override button is provided in case the user wishes to manually trigger flushing earlier. Some electronically triggered models also incorporate a true mechanical manual override which can be used in the event of the failure of the electronic system. In retrofit installations, a self-contained battery-powered or hard-wired unit can be added to an existing manual flushometer to flush automatically when a user departs. Once a flushometer valve has been flushed, and after a preset interval, the flushometer mechanism closes the valve and stops the flow. The flushometer system requires no storage tank, but uses a high rate of water flow for a very short time. Thus a inch (22 mm) pipe at minimum, or preferably a 1-inch (29 mm) pipe, must be used. Water main pressures must be above . The higher water pressure employed by a flushometer valve scours the bowl more efficiently than a gravity-driven system, and fewer blockages typically occur as a result of this higher water pressure. Flushometer systems require approximately the same amount of water as a gravity system to operate (1.6 gpf).


Bowl design

The "bowl" or "pan" of a toilet is the receptacle that receives bodily waste. A toilet bowl is most often made of a
ceramic A ceramic is any of the various hard, brittle, heat-resistant and corrosion-resistant materials made by shaping and then firing an inorganic, nonmetallic material, such as clay, at a high temperature. Common examples are earthenware, porcelain, ...
, but can sometimes be made of stainless steel or composite plastics. Toilet bowls are mounted in any one of three basic manners: above-floor mounted (
pedestal A pedestal (from French ''piédestal'', Italian ''piedistallo'' 'foot of a stall') or plinth is a support at the bottom of a statue, vase, column, or certain altars. Smaller pedestals, especially if round in shape, may be called socles. In ...
), wall mounted (
cantilever A cantilever is a rigid structural element that extends horizontally and is supported at only one end. Typically it extends from a flat vertical surface such as a wall, to which it must be firmly attached. Like other structural elements, a cant ...
), or in-floor mounted ( squat toilet). Within the bowl, there are three main waterway design systems: the siphoning trapped system (found primarily in North American residential installations, and in North American light commercial installations), the non-siphoning trapped system (found in most other installations), and the valve-closet system (found in trains, passenger aircraft, buses, and other such installations around the world). Older style toilets called "washout" toilets are now only found in a few locations.


Siphonic bowls


Single trap siphonic toilet

The siphonic toilet, also called "siphon jet" and "siphon wash", is perhaps the most popular design in North America for residential and light commercial toilet installations. All siphonic toilets incorporate an "S" shaped waterway. Standing water in the bowl acts as a barrier to
sewer gas Sewer gas is a complex, generally obnoxious smelling mixture of toxic and nontoxic gases produced and collected in sewage systems by the decomposition of organic household or industrial wastes, typical components of sewage. Sewer gases may inclu ...
coming out of the sewer through the drain, and also as a receptacle for waste. Sewer gas is vented through a separate vent pipe attached to the sewer line. The water in the toilet bowl is connected to the drain by a drainpipe shaped like an extended "S" which curves up behind the bowl and down to the drain. The portion of the channel behind the bowl is arranged as a
siphon A siphon (from grc, σίφων, síphōn, "pipe, tube", also spelled nonetymologically syphon) is any of a wide variety of devices that involve the flow of liquids through tubes. In a narrower sense, the word refers particularly to a tube in a ...
tube, whose length is greater than the depth of the water in the bowl. The top of the curving tube limits the height of the water in the bowl before it flows down the drain. The waterways in these toilets are designed with slightly smaller diameters than a non-siphonic toilet, so that the waterway will naturally fill up with water each time it is flushed, creating the siphon action. At the top of the toilet bowl is a rim with many angled drain holes that are fed from the tank, which fill, rinse, and induce swirling in the bowl when it is flushed. Some designs use a large hole in the front of the rim to allow faster filling of the bowl. There may also be a siphon jet hole about diameter in the bottom of the toilet bowl trap. If the toilet is flushed from a tank, a large holding cistern is mounted above the toilet, containing approximately of water in modern designs. This tank is built with a large drain diameter hole at its bottom covered by a flapper valve that allows the water to rapidly leave the holding tank when the flush is activated. Alternatively, water may be supplied directly via a flush valve or "flushometer". The rapid influx of water into the bowl causes the standing water in the bowl to rise and fill the S-shaped siphon tube mounted in the back of the toilet. This starts the toilet's siphonic action. The siphon action quickly "pulls" nearly all of the water and waste in the bowl and the on-rushing tank water down the drain in about 4–7 seconds —it flushes. When most of the water has drained out of the bowl, the continuous column of water through the siphon is broken when air enters the siphon tube. The toilet then gives its characteristic gurgle as the siphonic action ceases and no more water flows out of the toilet. A "true siphonic toilet" can be easily identified by the noise it makes. If it can be heard to suck air down the drain at the end of a flush, then it is a true siphonic toilet. If not, then it is either a double trap siphonic or a non-siphonic toilet. If water is poured slowly into the bowl it simply flows over the rim of the waterway and pours slowly down the drain—thus the toilet does not flush properly. After flushing, the flapper valve in the water tank closes or the flush valve shuts; water lines and valves connected to the water supply refill the toilet tank and bowl. Then the toilet is again ready for use. Note with this flush design: With age the forward ("flush") jet connection to the upper inlet in the toilet may slowly clog and (over many years) eventually lead to poor, or no flushing action – despite the fact that the main bowl's exit pipe and the toilet's air vent are both open. A test for this is if a "normal flush" evacuation of the bowl occurs when a large amount of water is poured into the bowl at a fast rate. If test is positive, yet the normal full tank flush, in comparison, has diminished flow; or after time no flush, One should check if the flush jet is clogged – leading to the need to snake the jet tube to restart normal flush function or replace the toilet entirely.


Double trap siphonic toilet

The double trap siphonic toilet is a less common type that is exceptionally quiet when flushed. A device known as an aspirator uses the flow of water in a flush to pull air from the cavity between the two traps, reducing the air pressure inside and creating a siphon which pulls water and waste from the toilet bowl. Towards the end of the flush cycle the aspirator ceases being immersed in water, thus allowing air to enter the cavity between the traps and breaking the siphon, without the noise while the final flush water fills the pan.


Non-siphonic bowls


Washdown toilet

Washdown toilets are the most common form of pedestal and cantilever toilets outside the Americas. The bowl has a large opening at the top which tapers down to a water trap at the base. It is flushed from the top by water discharged through a flushing rim or jets. The force of the water flowing into the bowl washes the waste through the trap and into the drains. Washdown bowls developed from earlier "hopper" closets, which were simple conical bowls connected to a drain. However, waste is typically excreted towards the back of the toilet, rather than the exact center, and the backs of the hoppers were prone to becoming soiled. The modern washdown bowl has a steeply sloping back and a more gently sloping or curving front, so the water trap is off-center, towards the rear of the toilet. With this "eccentric cone" design, most waste drops into the pool of water at the base of the bowl, rather than onto the surface of the toilet. Early washdown closets had a large water area at the base to minimize soiling, which required a large volume of water to clear them effectively. Modern bowls have a smaller area, which reduces the volume of water needed to flush them; however, that water area is always small compared to the water area of a typical North American siphonic bowl, and this makes the washdown bowl prone to soiling.


Washout toilet

Washout, or ''Flachspüler'' ("shallow flush"), toilets have a flat platform with a shallow pool of water. They are flushed by a jet of water from the back that drives waste into the trap below. From there, the water flow removes it into the sewage system. An advantage of the design is that users will not get splashed from below. Taking of stool samples is also simplified. Washout toilets have a shallow pool of water into which waste is deposited, with a trapped drain just behind this pool. Waste is cleared out from this pool of water by being swept over into the trap (usually either a P-trap or an S-trap) and then beyond into a sewer by water from the flush. Washout pans were among the first types of ceramic toilets invented and since the early 1970s are now only found in a decreasing number of localities in Europe. A washout toilet is a kind of flush toilet which was once predominantly used in Germany, Austria and France. It was patented in Britain by George Jennings in 1852 and remained the standard toilet type in Britain throughout the 19th century. Examples of this type of toilet can be found in Austria, the Czech Republic, Germany, Hungary, the Netherlands, and some regions of Poland, although it is becoming less common. One disadvantage of this design is that it may require the more intense use of a toilet brush to remove bits of feces that may have left marks on the shelf. Additionally, this design presents the disadvantage of creating a strong lingering odor since the feces are not submerged in water immediately after excretion. Similar designs are found in some early toilets in the US, one particular brand being labeled the "Grand Niagara", as the flushing of the shelf created a waterfall effect into the drain chamber.


Squat toilet

In many parts of Asia, people traditionally use the toilet in a
squatting position Squatting is a versatile posture where the weight of the body is on the feet but the knees and hips are bent. In contrast, sitting involves taking the weight of the body, at least in part, on the buttocks against the ground or a horizontal object ...
. This applies to defecation and urination by males and females. Therefore, homes and public washrooms have squat toilets, with the toilet bowl installed in the floor. This has the advantages of not needing an additional toilet seat and also being more convenient for cultures where people use water to wash their genitals instead of toilet paper. However, Western-style toilets that are mounted at sitting height and have a plastic seat have become popular as well. Many public washrooms have both squatting and sitting toilets. In Western countries, instructions have been put up in some
public toilet A public toilet, restroom, public bathroom or washroom is a room or small building with toilets (or urinals) and sinks for use by the general public. The facilities are available to customers, travelers, employees of a business, school pupils ...
s used by people accustomed to squat toilets, on the correct use of a sitting-style toilet. This is to avoid breaking the toilet or seat if someone attempts to squat on the edges. The "Anglo-Indian" design used in India allows the same toilet to be used in the sitting or the squatting position.


Valve closet

The valve closet has a valve or flap at the exit of the bowl, often with a watertight seal to retain a pool of water in the pan. When the toilet is flushed, the valve is opened and the water in the pan flows rapidly out of the bowl into the drains, carrying the waste with it. The earliest type of toilet, the valve closet is now rarely used for water-flush toilet systems. More complicated in design than other toilets, this design has lower reliability and is more difficult to maintain or repair. The most common use for valve closets is now in portable closets for caravans, camping, trains, and aircraft, where the flushing fluid is recycled. This design is also used in train carriages for use in areas where the waste is allowed to be simply dumped between the tracks (the flushing of such toilets is generally prohibited when the train is in a station). Simple valve closets are used on most older style Russian trains, made in Eastern Germany ( factory, design dated probably to the 1950s), employing a pan-like shutter valve at the base of the pan and discharging waste directly onto the trackbed below. Usage of this type of toilet is permitted only while the train is moving, and outside of major cities. These designs are being phased out, together with the old trains, and are being replaced with modern vacuum systems. The British singer Ian Wallace composed and performed the humorous song "Never Do It at the Station", which mentioned the old-fashioned trackbed dumping toilets which were still in use during the mid-20th century in Britain. The song first advised frugal travelers to save money by avoiding
pay toilet A pay toilet is a public toilet that requires the user to pay. It may be street furniture or be inside a building, e.g. a shopping mall, department store, or railway station. The reason for charging money is usually for the maintenance of the eq ...
s in train stations, but also reminded polite passengers not to use the onboard "loo" while the train was stopped at a station.


Low-flow and high-efficiency flush toilets

Since 1994, there is a significant move towards using less water for flushing toilets. This has resulted in the emergence of low flush toilet designs and local or national standards on
water consumption A water footprint shows the extent of water use in relation to consumption by people. The water footprint of an individual, community, or business is defined as the total volume of fresh water used to produce the goods and services consumed by th ...
for flushing. As an alternative some people modify an existing high flush toilet to use less water by placing a brick or water bottle into the toilet's water tank. Other modifications are often done on the water system itself (such as by using
greywater Greywater (or grey water, sullage, also spelled gray water in the United States) refers to domestic wastewater generated in households or office buildings from streams without fecal contamination, i.e., all streams except for the wastewater fro ...
), or a system that pollutes the water less, for more efficient water use.
Urine diversion Urine diversion, also called urine separation or source separation, refers to the separate collection of human urine and feces at the point of their production, i.e. at the toilet or urinal. Separation of urine from feces allows human waste t ...
flush toilets, which were developed in Sweden, save water by using less water, or even no water, for the urine flush compared to about six litres for the feces flush.


US standards for new toilets

Pre-1994 residential and pre-1997 commercial flush toilets in the United States typically used of water per flush (gpf or lpf). The
United States Congress The United States Congress is the legislature of the federal government of the United States. It is Bicameralism, bicameral, composed of a lower body, the United States House of Representatives, House of Representatives, and an upper body, ...
passed the
Energy Policy Act of 1992 The Energy Policy Act of 1992, effective October 24, 1992, (102nd Congress H.R.776.ENR, abbreviated as EPACT92) is a United States government act. It was passed by Congress and set goals, created mandates, and amended utility laws to increase c ...
, which mandated that from 1994 common flush toilets use only . In response to the Act, manufacturers produced ''low-flow'' toilets, which many consumers did not like because they often required more than one flush to remove solids. People unhappy with the reduced performance of the low-flow toilets resorted to driving across the border to Canada or Mexico or buying salvaged toilets from older buildings. Manufacturers responded to consumers' complaints by improving the toilets. The improved products are generally identified as ''high efficiency toilets'' or HETs. HETs possess an effective flush volume of or less. They may be ''single-flush'' or ''dual-flush''. A dual-flush toilet permits selection between different amounts of water for solid or liquid waste. Some HETs are ''pressure-assisted'' (or power, pump, or vacuum assisted). The performance of a flush-toilet may be rated by a Maximum Performance (MaP) score. The low end of MaP scores is 250 (250 grams of simulated fecal matter). The high end of MaP scores is 1000. A toilet with a MaP score of 1000 should provide trouble-free service. It should remove all waste with a single flush; it should not plug; it should not harbor any odor; it should be easy to keep clean. The United States
Environmental Protection Agency A biophysical environment is a biotic and abiotic surrounding of an organism or population, and consequently includes the factors that have an influence in their survival, development, and evolution. A biophysical environment can vary in scale ...
uses a MaP score of 350 as the minimum performance threshold for HETs. 1.6 gpf toilets are also sometimes referred as Ultra Low Flow (ULF). Methods used to make up for the inadequacies of low flow toilets include using thinner toilet paper, plungers, and adding extra cups of water to the bowl manually.


Maintenance and hygiene


Clogging

If clogging occurs, it is usually the result of an attempt to flush unsuitable items, or as feces size often increases with age or too much toilet paper. Clogging can occur spontaneously due to limescale fouling of the drain pipe, or by overloading the stool capacity of the toilet. Stool capacity varies among toilet designs and is based on the size of the drainage pipe, the capacity of the water tank, the velocity of a flush, and the method by which the water attempts to vacate the bowl of its contents. The size and consistency of the stool is a hard-to-predict contributory factor. In some countries, clogging has become more frequent due to regulations that require the use of small-tanked low-flush toilets in attempt to conserve water. Designs which increase the velocity of flushed water or improve the travel path can improve low-flow reliability. Partial clogging is particularly insidious, as it is usually not discovered immediately, but only later by an unsuspecting user trying to flush an incompletely emptied toilet. Overflowing of the water mixed with excrement may then occur, depending on the bowl volume, tank capacity and severity of clogging. For this reason, rooms with flush toilets may be designed as wet rooms, with a second drain on the floor, and a shower head capable of reaching the whole floor area. Common means to remedy clogging include use of a toilet plunger, drain cleaner, or a plumber's snake.


Aerosols

A "toilet plume" is the dispersal of microscopic particles as a result of flushing a toilet. Normal use of a toilet by healthy people is considered unlikely to be a major health risk. There is indirect evidence that specific pathogens such as
norovirus Norovirus, sometimes referred to as the winter vomiting disease, is the most common cause of gastroenteritis. Infection is characterized by non-bloody diarrhea, vomiting, and stomach pain. Fever or headaches may also occur. Symptoms usually devel ...
or SARS coronavirus could potentially be spread through toilet aerosols, but as of 2015 no direct experimental studies had clearly demonstrated or refuted actual disease transmission from toilet aerosols. It has been hypothesized that dispersal of pathogens may be reduced by closing the toilet lid before flushing, and by using toilets with lower flush energy.


History


Pre-modern flush toilet systems

Forms of water flushed latrines have been found to exist since the
Neolithic The Neolithic period, or New Stone Age, is an Old World archaeological period and the final division of the Stone Age. It saw the Neolithic Revolution, a wide-ranging set of developments that appear to have arisen independently in several pa ...
. The oldest neolithic village in Britain, dating from circa 31st century BC,
Skara Brae Skara Brae is a stone-built Neolithic settlement, located on the Bay of Skaill on the west coast of Mainland, the largest island in the Orkney archipelago of Scotland. Consisting of ten clustered houses, made of flagstones, in earthen dam ...
,
Orkney Orkney (; sco, Orkney; on, Orkneyjar; nrn, Orknøjar), also known as the Orkney Islands, is an archipelago in the Northern Isles of Scotland, situated off the north coast of the island of Great Britain. Orkney is 10 miles (16 km) north ...
, used a form of hydraulic technology for
sanitation Sanitation refers to public health conditions related to clean drinking water and treatment and disposal of human excreta and sewage. Preventing human contact with feces is part of sanitation, as is hand washing with soap. Sanitation syste ...
. The village's design used a stream, and connecting drainage system to wash waste away. The Mesopotamians introduced the world to clay sewer pipes around 4000 BCE, with the earliest examples found in the Temple of Bel at
Nippur Nippur ( Sumerian: ''Nibru'', often logographically recorded as , EN.LÍLKI, "Enlil City;"The Cambridge Ancient History: Prolegomena & Prehistory': Vol. 1, Part 1. Accessed 15 Dec 2010. Akkadian: ''Nibbur'') was an ancient Sumerian city. It was ...
and at
Eshnunna Eshnunna (modern Tell Asmar in Diyala Governorate, Iraq) was an ancient Sumerian (and later Akkadian) city and city-state in central Mesopotamia 12.6 miles northwest of Tell Agrab and 15 miles northwest of Tell Ishchali. Although situated in the ...
, utilised to remove wastewater from sites, and capture rainwater, in wells. The city of
Uruk Uruk, also known as Warka or Warkah, was an ancient city of Sumer (and later of Babylonia) situated east of the present bed of the Euphrates River on the dried-up ancient channel of the Euphrates east of modern Samawah, Muthanna Governorate, Al ...
hosts the earliest known examples of brick constructed
Latrine A latrine is a toilet or an even simpler facility that is used as a toilet within a sanitation system. For example, it can be a communal trench in the earth in a camp to be used as emergency sanitation, a hole in the ground ( pit latrine), or ...
s, both squat and pedestal, from 3200 BCE. Clay pipes were later used in the Hittite city of
Hattusa Hattusa (also Ḫattuša or Hattusas ; Hittite: URU''Ḫa-at-tu-ša'', Turkish: Hattuşaş , Hattic: Hattush) was the capital of the Hittite Empire in the late Bronze Age. Its ruins lie near modern Boğazkale, Turkey, within the great loop of ...
. They had easily detachable and replaceable segments, and allowed for cleaning. Flushed toilet systems were constructed by people of the
Indus Civilization The Indus Valley Civilisation (IVC), also known as the Indus Civilisation was a Bronze Age civilisation in the northwestern regions of South Asia, lasting from 3300 BCE to 1300 BCE, and in its mature form 2600 BCE to 1900 ...
at some places, and later Egyptians and the
Minoan civilization The Minoan civilization was a Bronze Age Aegean civilization on the island of Crete and other Aegean Islands, whose earliest beginnings were from 3500BC, with the complex urban civilization beginning around 2000BC, and then declining from 1450 ...
did so next, while the latter developed by the second millennium BC flushable pedestal toilets, with examples excavated at
Knossos Knossos (also Cnossos, both pronounced ; grc, Κνωσός, Knōsós, ; Linear B: ''Ko-no-so'') is the largest Bronze Age archaeological site on Crete and has been called Europe's oldest city. Settled as early as the Neolithic period, the na ...
and Akrotiri. Communal latrines were in use throughout the
Roman Empire The Roman Empire ( la, Imperium Romanum ; grc-gre, Βασιλεία τῶν Ῥωμαίων, Basileía tôn Rhōmaíōn) was the post-Roman Republic, Republican period of ancient Rome. As a polity, it included large territorial holdings aro ...
, feeding into either primary or secondary sewers, from the first through fifth centuries AD. A very well-preserved example are the latrines at
Housesteads Housesteads Roman Fort is the remains of an auxiliary fort on Hadrian's Wall, at Housesteads, Northumberland, England, south of Broomlee Lough. The fort was built in stone around AD 124, soon after the construction of the wall began in AD 1 ...
on
Hadrian's Wall Hadrian's Wall ( la, Vallum Aelium), also known as the Roman Wall, Picts' Wall, or ''Vallum Hadriani'' in Latin, is a former defensive fortification of the Roman province of Britannia, begun in AD 122 in the reign of the Emperor Hadrian. Ru ...
in Britain. Such toilets did not flush in the modern sense, but had a continuous stream of running water to wash away waste. With the fall of the Western Roman Empire, these communal toilet systems fell into disuse in Western Europe, though continued in the Eastern Byzantine Roman Empire, with records of toilet pipes being renewed, and sewers repaired. In the
Muslim world The terms Muslim world and Islamic world commonly refer to the Islamic community, which is also known as the Ummah. This consists of all those who adhere to the religious beliefs and laws of Islam or to societies in which Islam is practiced. I ...
during the
Islamic Golden Age The Islamic Golden Age was a period of cultural, economic, and scientific flourishing in the history of Islam, traditionally dated from the 8th century to the 14th century. This period is traditionally understood to have begun during the reign ...
(8th–14th centuries), cities had flush toilets connected to
water supply Water supply is the provision of water by public utilities, commercial organisations, community endeavors or by individuals, usually via a system of pumps and pipes. Public water supply systems are crucial to properly functioning societies. Th ...
and
waste disposal Waste management or waste disposal includes the processes and actions required to manage waste from its inception to its final disposal. This includes the collection, transport, treatment and disposal of waste, together with monitorin ...
sewer systems. The city of
Fustat Fusṭāṭ ( ar, الفُسطاط ''al-Fusṭāṭ''), also Al-Fusṭāṭ and Fosṭāṭ, was the first capital of Egypt under Muslim rule, and the historical centre of modern Cairo. It was built adjacent to what is now known as Old Cairo by t ...
in Egypt, for example, had multi-storey
tenement A tenement is a type of building shared by multiple dwellings, typically with flats or apartments on each floor and with shared entrance stairway access. They are common on the British Isles, particularly in Scotland. In the medieval Old Town, i ...
buildings (with up to six floors) with flush toilets, which were connected to a water supply system, and flues on each floor carrying waste to underground channels.


Development of the modern flush toilet

In 1596 Sir John Harington (1561–1612) published ''A New Discourse of a Stale Subject, Called the Metamorphosis of Ajax'', describing a forerunner to the modern flush toilet installed at his house at Kelston in
Somerset ( en, All The People of Somerset) , locator_map = , coordinates = , region = South West England , established_date = Ancient , established_by = , preceded_by = , origin = , lord_lieutenant_office =Lord Lieutenant of Somerset , lor ...
. The design had a flush valve to let water out of the tank, and a wash-down design to empty the bowl. He installed one for his godmother
Queen Elizabeth I Elizabeth I (7 September 153324 March 1603) was Queen of England and Ireland from 17 November 1558 until her death in 1603. Elizabeth was the last of the five House of Tudor monarchs and is sometimes referred to as the "Virgin Queen". Eli ...
at Richmond Palace. With the onset of the
Industrial Revolution The Industrial Revolution was the transition to new manufacturing processes in Great Britain, continental Europe, and the United States, that occurred during the period from around 1760 to about 1820–1840. This transition included going f ...
and related advances in technology, the flush toilet began to emerge into its modern form. A crucial advance in plumbing was the S-trap, invented by the Scottish mechanic
Alexander Cumming Alexander Cumming FRSE (sometimes referred to as Alexander Cummings; 1733 – 8 March 1814) was a Scottish watchmaker and instrument inventor, who was the first to patent a design of the flush toilet in 1775, which had been pioneered by Sir ...
in 1775, and still in use today. This device uses the standing water to seal the outlet of the bowl, preventing the escape of foul air from the sewer. His design had a sliding valve in the bowl outlet above the trap. Two years later, Samuel Prosser applied for a British patent for a "plunger closet". Prolific inventor
Joseph Bramah Joseph Bramah (13 April 1748 – 9 December 1814), born Stainborough Lane Farm, Stainborough, in Barnsley, Yorkshire, was an English inventor and locksmith. He is best known for having improved the flush toilet and inventing the hydraulic p ...
began his professional career installing water closets (toilets) that were based on Alexander Cumming's patented design of 1775. He found that the current model being installed in London houses had a tendency to freeze in cold weather. In collaboration with a Mr. Allen, he improved the design by replacing the usual slide valve with a hinged flap that sealed the bottom of the bowl. He also developed a float valve system for the flush tank. Obtaining the patent for it in 1778, he began making toilets at a workshop in Denmark Street,
St Giles Saint Giles (, la, Aegidius, french: Gilles), also known as Giles the Hermit, was a hermit or monk active in the lower Rhône most likely in the 6th century. Revered as a saint, his cult became widely diffused but his hagiography is mostly lege ...
. The design was arguably the first practical non-manual flush toilet, and production continued well into the 19th century, used mainly on boats. Thomas Bowdich, an English traveller, visited
Kumasi Kumasi (historically spelled Comassie or Coomassie, usually spelled Kumase in Twi) is a city in the Ashanti Region, and is among the largest metropolitan areas in Ghana. Kumasi is located in a rain forest region near Lake Bosomtwe, and is t ...
, capital of the Ashanti Empire in 1817 and mentioned that majority of the houses in the city especially those near the king's palace included indoor toilets that were flushed with gallons of boiling water.


Industrial production

It was only in the mid-19th century, with growing levels of urbanisation and industrial prosperity, that the flush toilet became a widely used and marketed invention. This period coincided with the dramatic growth in the sewage system, especially in
London London is the capital and List of urban areas in the United Kingdom, largest city of England and the United Kingdom, with a population of just under 9 million. It stands on the River Thames in south-east England at the head of a estuary dow ...
, which made the flush toilet particularly attractive for health and sanitation reasons. George Jennings established a business manufacturing water closets, salt-glaze drainage, sanitary pipes and sanitaryware at Parkstone Pottery in the 1840s, where he popularized the flush toilet to the middle class. At
The Great Exhibition The Great Exhibition of the Works of Industry of All Nations, also known as the Great Exhibition or the Crystal Palace Exhibition (in reference to the temporary structure in which it was held), was an international exhibition which took pl ...
at Hyde Park held from 1 May to 15 October 1851, George Jennings installed his Monkey Closets in the Retiring Rooms of
The Crystal Palace The Crystal Palace was a cast iron and plate glass structure, originally built in Hyde Park, London, Hyde Park, London, to house the Great Exhibition of 1851. The exhibition took place from 1 May to 15 October 1851, and more than 14,000 exhibit ...
. These were the first public
pay toilet A pay toilet is a public toilet that requires the user to pay. It may be street furniture or be inside a building, e.g. a shopping mall, department store, or railway station. The reason for charging money is usually for the maintenance of the eq ...
s (free ones did not appear until later), and they caused great excitement. During the exhibition, 827,280 visitors paid one penny to use them; for the penny they got a clean seat, a towel, a comb, and a
shoe shine Shoe polish (or boot polish) is a waxy paste, cream, or liquid that is used to polish, shine, and waterproof leather shoes or boots to extend the footwear's life and restore its appearance. Shoe polishes are distinguished by their textures, wh ...
. "To spend a penny" became a
euphemism A euphemism () is an innocuous word or expression used in place of one that is deemed offensive or suggests something unpleasant. Some euphemisms are intended to amuse, while others use bland, inoffensive terms for concepts that the user wishes ...
, for going to the toilet. When the exhibition finished and moved to Sydenham, the toilets were to be closed down. However, Jennings persuaded the organisers to keep them open, and the toilet went on to earn over £1000 a year. He opened the first underground convenience at the Royal Exchange in 1854. He received a patent in 1852 for an improved construction of water-closet, in which the pan and trap were constructed in the same piece, and so formed that there was always a small quantity of water retained in the pan itself, in addition to that in the trap which forms the water-joint. He also improved the construction of valves, drain traps, forcing pumps and pump-barrels. By the end of the 1850s building codes suggested that most new middle-class homes in British cities were equipped with a water closet. Another pioneering manufacturer was Thomas William Twyford, who invented the single piece, ceramic flush toilet.David J. Eveleigh, ‘Twyford, Thomas William (1849–1921)’, Oxford Dictionary of National Biography, Oxford University Press, May 2009; online edn, May 2011 The 1870s proved to be a defining period for the sanitary industry and the water closet; the debate between the simple water closet trap basin made entirely of earthenware and the very elaborate, complicated and expensive mechanical water closet would fall under public scrutiny and expert opinion. In 1875 the "wash-out" trap water closet was first sold, and was found as the public's preference for basin type water closets. By 1879 Twyford had devised his own type of the "wash out" trap water closet; he titled it the "National", and it became the most popular wash-out water closet. By the 1880s the free-standing water closet was on sale and quickly gained popularity; the free-standing water closet was able to be cleaned more easily and was therefore a more hygienic water closet. Twyford's "Unitas" model was free-standing and made completely of earthenware. Throughout the 1880s he submitted further patents for improvements to the flushing rim and the outlet. Finally, in 1888 he applied for a patent protection for his "after flush" chamber; the device allowed the basin to be refilled by a lower quantity of clean water in reserve after the water closet was flushed. The modern pedestal "flush-down" toilet was demonstrated by Frederick Humpherson of the Beaufort Works, Chelsea, England in 1885. The leading companies of the period issued catalogues, established showrooms in department stores and marketed their products around the world. Twyford had showrooms for water closets in
Berlin Berlin ( , ) is the capital and largest city of Germany by both area and population. Its 3.7 million inhabitants make it the European Union's most populous city, according to population within city limits. One of Germany's sixteen constitu ...
, Germany;
Sydney Sydney ( ) is the capital city of the state of New South Wales, and the most populous city in both Australia and Oceania. Located on Australia's east coast, the metropolis surrounds Sydney Harbour and extends about towards the Blue Mounta ...
, Australia; and
Cape Town Cape Town ( af, Kaapstad; , xh, iKapa) is one of South Africa's three capital cities, serving as the seat of the Parliament of South Africa. It is the legislative capital of the country, the oldest city in the country, and the second largest ...
, South Africa. The
Public Health Act 1875 The Public Health Act 1875c 55 is an Act of the Parliament of the United Kingdom, one of the Public Health Acts, and a significant step in the advancement of public health in England. Its purpose was to codify previous measures aimed at combatin ...
set down stringent guidelines relating to sewers, drains, water supply and toilets and lent tacit government endorsement to the prominent water closet manufacturers of the day. Contrary to popular legend, Sir Thomas Crapper did not invent the flush toilet. He was, however, in the forefront of the industry in the late 19th century, and held nine patents, three of them for water closet improvements such as the floating
ballcock A ballcock (also balltap or float valve) is a mechanism or machine for filling water tanks, such as those found in flush toilets, while avoiding overflow and (in the event of low water pressure) backflow. The modern ballcock was invented by J ...
. His flush toilets were designed by inventor Albert Giblin, who received a British patent for the "Silent Valveless Water Waste Preventer", a siphon discharge system. Crapper popularized the siphon system for emptying the tank, replacing the earlier floating valve system which was prone to leaks.


Spread and further developments

Although flush toilets first appeared in Britain, they soon spread to the
Continent A continent is any of several large landmasses. Generally identified by convention rather than any strict criteria, up to seven geographical regions are commonly regarded as continents. Ordered from largest in area to smallest, these seven ...
. The first such examples may have been the three "waterclosets" installed in the new town house of banker ''Nicolay August Andresen'' on 6 Kirkegaten in Christiania, insured in January 1859. The toilets were probably imported from Britain, as they were referred to by the English term "waterclosets" in the insurance ledger. Another early watercloset on the European continent, dating from 1860, was imported from Britain to be installed in the rooms of
Queen Victoria Victoria (Alexandrina Victoria; 24 May 1819 – 22 January 1901) was Queen of the United Kingdom of Great Britain and Ireland from 20 June 1837 until her death in 1901. Her reign of 63 years and 216 days was longer than that of any previ ...
in Ehrenburg Palace (
Coburg Coburg () is a town located on the Itz river in the Upper Franconia region of Bavaria, Germany. Long part of one of the Thuringian states of the Wettin line, it joined Bavaria by popular vote only in 1920. Until the revolution of 1918, it ...
, Germany); she was the only one who was allowed to use it. In America, the chain-pull indoor toilet was introduced in the homes of the wealthy and in hotels, soon after its invention in England in the 1880s. Flush toilets were introduced in the 1890s. William Elvis Sloan invented the Flushometer in 1906, which used pressurized water directly from the supply line for faster recycle time between flushes. The Flushometer is still in use today in public restrooms worldwide. The vortex-flushing toilet bowl, which creates a self-cleansing effect, was invented by Thomas MacAvity Stewart of
Saint John, New Brunswick Saint John is a seaport city of the Atlantic Ocean located on the Bay of Fundy in the province of New Brunswick, Canada. Saint John is the oldest incorporated city in Canada, established by royal charter on May 18, 1785, during the reign of ...
in 1907. Philip Haas of
Dayton Dayton () is the sixth-largest city in the U.S. state of Ohio and the county seat of Montgomery County. A small part of the city extends into Greene County. The 2020 U.S. census estimate put the city population at 137,644, while Greater Da ...
,
Ohio Ohio () is a U.S. state, state in the Midwestern United States, Midwestern region of the United States. Of the List of states and territories of the United States, fifty U.S. states, it is the List of U.S. states and territories by area, 34th-l ...
, made some significant developments, including the flush rim toilet with multiple jets of water from a ring and the water closet flushing and recycling mechanism similar to those in use today. The company
Caroma Caroma (Caroma Dorf) is an Australian designer and distributor of bathroom products. Caroma was established in 1941 by Hungarian-born Charles Rothauser, and since closing its last factory in 2017 now sources all products from third-party overseas ...
in Australia developed the Duoset cistern with two buttons and two flush volumes as a water-saving measure in 1980. Modern versions of the Duoset are now available worldwide, and save the average household 67% of their normal water usage.


Manufacture

A toilet's body is typically made from vitreous china, which starts out as an aqueous suspension of various minerals called a slip. It takes about of slip to make a toilet. This slip is poured into the space between
plaster of Paris Plaster is a building material used for the protective or decorative coating of walls and ceilings and for moulding and casting decorative elements. In English, "plaster" usually means a material used for the interiors of buildings, while "re ...
molds. The toilet bowl, rim, tank and tank lid require separate molds. The molds are assembled and set up for filling and the slip-filled molds sit for about an hour after filling. This allows the plaster molds to absorb moisture from the slip, which makes it semi-solid next to the mold surfaces but lets it remain liquid further from the surface of the molds. Then, the workers remove plugs to allow any excess liquid slip to drain from the cavities of the mold (this excess slip is recycled for later use). The drained-out slip leaves hollow voids inside the fixture, using less material to keep it both lighter and easier to fire in a
kiln A kiln is a thermally insulated chamber, a type of oven, that produces temperatures sufficient to complete some process, such as hardening, drying, or chemical changes. Kilns have been used for millennia to turn objects made from clay int ...
. This molding process allows the formation of intricate internal waste lines in the fixture; the drain's hollow cavities 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 then has appropriate slanted holes for the rinsing jets cut, and the mounting holes for tank and seat are punched into the rim piece. 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 is attached on top of the bowl so that 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 body 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 to remove the mold joints or roughness: this process is called "fettling". For large scale production pieces, these steps may be automated. The parts are then left outside or put in a warm room to dry, before going through a dryer at about , for about 20–36 hours.YouTube video of toilet manufacturing
Accessed 26 September 2011
After the surfaces are smoothed, 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 at the front, increasing towards the middle to over degrees, and exiting at about . 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. After the pieces are removed from the kiln and fully cooled, they are inspected for cracks or other defects. Then, 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 placed into the tank, with final assembly at installation. A two-piece attaching seat and toilet bowl lid are typically mounted over the bowl to allow covering the toilet when it is not in use and to provide seating comfort. The seat may be installed at the factory, or the parts may be sold separately and assembled by a plumbing distributor or the installer.


Water usage

The amount of water used by conventional flush toilets is usually a significant portion of personal daily water usage: for example, five 10-liter flushes per day use . Modern low-flush toilet designs allow the use of much less water per flush, per flush. Dual flush toilets allow the user to select between a flush for urine or feces, saving a significant amount of water over conventional units. Dual flush may be accomplished by pushing the flush handle up or down, or a two-segment flush pushbutton may be used whereby pressing the smaller section releases less water.


Flushing with non-potable water sources

Raw water flushing, including seawater flushing, is a method of
water conservation Water conservation includes all the policies, strategies and activities to sustainably manage the natural resource of fresh water, to protect the hydrosphere, and to meet the current and future human demand (thus avoiding water scarcity). Popula ...
, where
raw water Raw water is water found in the environment that has not been treated and does not have any of its minerals, ions, particles, bacteria, or parasites removed. Raw water includes rainwater, ground water, water from infiltration wells, and water fro ...
, such as
seawater Seawater, or salt water, is water from a sea or ocean. On average, seawater in the world's oceans has a salinity of about 3.5% (35 g/L, 35 ppt, 600 mM). This means that every kilogram (roughly one liter by volume) of seawater has appro ...
, is used for flush toilets. Such systems are used in places such as the majority of cities and towns in Hong Kong (see water supply and sanitation in Hong Kong),Seawater flushing to be extended to more Hong Kong toilets next year
South China Morning Post The ''South China Morning Post'' (''SCMP''), with its Sunday edition, the ''Sunday Morning Post'', is a Hong Kong-based English-language newspaper owned by Alibaba Group. Founded in 1903 by Tse Tsan-tai and Alfred Cunningham, it has remained ...
, 3 April 2014.
Gibraltar ) , anthem = " God Save the King" , song = "Gibraltar Anthem" , image_map = Gibraltar location in Europe.svg , map_alt = Location of Gibraltar in Europe , map_caption = United Kingdom shown in pale green , mapsize = , image_map2 = Gibr ...
, and
Avalon, California Avalon is the only incorporated city on Santa Catalina Island, in the California Channel Islands, and the southernmost city in Los Angeles County. The city is a resort community with the waterfront dominated by tourism-oriented businesses. T ...
, United States. Heads (on ships) are typically flushed with
seawater Seawater, or salt water, is water from a sea or ocean. On average, seawater in the world's oceans has a salinity of about 3.5% (35 g/L, 35 ppt, 600 mM). This means that every kilogram (roughly one liter by volume) of seawater has appro ...
. Flush toilets may, if plumbed for it, use
greywater Greywater (or grey water, sullage, also spelled gray water in the United States) refers to domestic wastewater generated in households or office buildings from streams without fecal contamination, i.e., all streams except for the wastewater fro ...
(water previously used for washing dishes, laundry and bathing) for flushing rather than drinkable
potable water Drinking water is water that is used in drink or food preparation; potable water is water that is safe to be used as drinking water. The amount of drinking water required to maintain good health varies, and depends on physical activity level, ...
.


Etymology


Water closet

The word "toilet" initially meant "wash-room", without reference to sanitary facilities. Early indoor toilets were known as
garderobe Garderobe is a historic term for a room in a medieval castle. The ''Oxford English Dictionary'' gives as its first meaning a store-room for valuables, but also acknowledges "by extension, a private room, a bed-chamber; also a privy". The word der ...
s because they were used to store clothes, as the smell of
ammonia Ammonia is an inorganic compound of nitrogen and hydrogen with the formula . A stable binary hydride, and the simplest pnictogen hydride, ammonia is a colourless gas with a distinct pungent smell. Biologically, it is a common nitrogenous ...
was found to deter fleas and moths. However, an
outhouse An outhouse is a small structure, separate from a main building, which covers a toilet. This is typically either a pit latrine or a bucket toilet, but other forms of dry (non-flushing) toilets may be encountered. The term may also be use ...
was usual until the nineteenth century, and only a few wealthy houses and luxury hotels had indoor toilets connected to drains and sewers. Lidded "chamber pots", kept in specially designed bedside cabinets and used in bedrooms by ladies and invalids, and portable bathtubs, could be emptied and washed in an
outhouse An outhouse is a small structure, separate from a main building, which covers a toilet. This is typically either a pit latrine or a bucket toilet, but other forms of dry (non-flushing) toilets may be encountered. The term may also be use ...
. From the sixteenth century in England, a private room (a closet) with a flushing toilet was referred to as a Water Closet ("WC"), in contrast with an Earth Closet ("EC"), an abbreviation still used in 1960s Oxfordshire cottage sales. The descriptive terms "wash-down closet" or "water closet" only reached the United States in the 1880s. By 1890 there was increased public awareness of disease and of carelessly disposed human waste being infectious. In common North American usage, a "bathroom" now invariably contains a toilet, but not usually a bath, to the confusion of foreigners. In the UK, Australia and NZ, "
Bathroom A bathroom or washroom is a room, typically in a home or other residential building, that contains either a bathtub or a shower (or both). The inclusion of a wash basin is common. In some parts of the world e.g. India, a toilet is typically ...
" or bath-room refers to a room with a fixed bathtub and not necessarily a toilet. The terms "bathroom", and "toilet" or “loo” (amongst other euphemisms) indicate distinct functions, although bathrooms may often include toilets. The term "water closet", now rarely used outside America, refers to a room that has both a toilet and other plumbing fixtures such as a sink or a bathtub. American Plumbers and codes use the term "water closet" or "WC" to differentiate toilets from urinals. Many European languages refer to a toilet as a "water" or "WC". The Royal Spanish Academy Dictionary accepts "váter" as a name for a toilet or bathroom, which is derived from the British term "water closet". France uses the expressions ''aller aux waters'' ("to go to the waters") derived from "water closet", and "w.-c." . Likewise the Romanian word "veceu" , and the Finnish word "vessa" derive from a shortened version of the abbreviation. In German, the expression "Klo" (first syllable of "Klosett") is used alongside "WC". In Italian WC or , and "water" , are very common terms to refer to the flushing toilet.


Society and culture


Swirl direction myth

It is a commonly held misconception that when flushed, the water in a toilet bowl swirls one way if the toilet is north of the equator and the other way if south of the equator, due to the
Coriolis effect In physics, the Coriolis force is an inertial or fictitious force that acts on objects in motion within a frame of reference that rotates with respect to an inertial frame. In a reference frame with clockwise rotation, the force acts to the ...
– usually, counter clockwise in the northern hemisphere, and clockwise in the southern hemisphere. In reality, the direction that the water takes is much more determined by the direction that the bowl's rim jets are pointed, and it can be made to flush in either direction in either hemisphere by simply redirecting the rim jets during manufacture. The relative importance of the Coriolis force can be determined by a ratio known as the Rossby number. When this number is much larger than 1, the Coriolis force is insignificant compared to the inertia effects. On the scale of bathtubs and toilets, the Rossby number is on the order of billions, and so the Coriolis effect is too weak to be observed except under carefully controlled laboratory conditions.


Courtesy flush

Since the 1990s, the slang term "courtesy flush" refers to a mid-defecation flush of the toilet as a courtesy to other bathroom users or other prisoners in a cell. A courtesy flush can serve to reduce odor and cover noise.


See also

*
Toilets in Japan Some toilets in Japan are more elaborate than toilets commonly found in other developed nations. European countries often have a toilet and a bidet separate whilst Japan combines an electronic bidet with the toilet. The current state of the art ...
* Thomas Maddock, started the American indoor toilet industry


References


External links

{{DEFAULTSORT:Flush Toilet Bathrooms British inventions Inventions of the Indus Valley civilisation 16th-century inventions