Cremation is the process of reducing dead bodies to basic chemical compounds in the form of gases and bone fragments. This is accomplished through high temperatures and vaporization. Contrary to popular belief, the cremated remains are not ashes in the usual sense, but rather dried bone fragments that have been pulverized, typically in a device called an electric cremated remains processor (known as a cremulator -see below- or pulverization may be done by hand). This leaves the bone in a fine sand like texture and color, able to be scattered without need for mixing with any foreign matter. Their weight is approximately 4 pounds (1.8 kg) for adult human females and 6 pounds (2.7 kg) for adult human males.
Cremation may serve as a funeral or postfuneral rite that is an alternative to the interment of an intact body in a casket. Cremated remains, which are not a health risk, may be buried or immured in memorial sites or cemeteries, or they may be legally retained by relatives or dispersed (scattered) in a variety of ways and locations with special permits or through a Scattering Service.
In many countries cremation is usually done in a crematory (or crematorium), but others may prefer different methods. An example is the common practice of open-air cremation in India.
Modern cremation process
The cremation occurs in a crematory (or crematorium), consisting of one or more cremator furnaces or cremation retorts for the ashes. A cremator is an industrial furnacecapable of generating temperatures of 870–980 °C (1,598–1,796 °F) to ensure disintegration of the corpse. A crematorium may be part of chapel or a funeral home, or part of an independent facility or a service offered by a cemetery.
Modern cremator fuels include natural gas and propane. However, coal and coke were used until the early 1960s.
Modern cremators have adjustable control systems that monitor the furnace during cremation. These systems automatically monitor the interior to tell when the cremation process is complete, after which the furnace shuts down automatically. The time required for cremation thus varies from body to body, and in modern furnaces may be as fast as one hour per 45 kilograms (99 lb) of body weight.
The chamber where the body is placed is called the retort and is lined with heat-resistant refractory bricks. The coffin or container is inserted (charged) into the retort as quickly as possible to avoid heat loss through the top-opening door. The container may be mounted on a charger (motorized trolley) that can quickly insert the container or on a fixed or movable hopper that allows the container to slide into the cremator.
Modern cremators are computer-controlled to ensure legal and safe use. For example, the retort door cannot be opened until the cremator has reached its operating temperature, and United States federal regulations require that newly constructed cremators feature dual electrical and mechanical heat shutoff switches and door releases accessible from inside the retort. Refractory bricks are typically replaced every five years because thermal fatigue gradually introduces fissures reducing their insulating strength.
Some crematoria allow relatives to view the charging. This is sometimes done for religious reasons, such as in traditional Hindu and Jain funerals.
Most cremators are a standard size. Typically, larger cities have access to an oversize cremator that can handle deceased in the 200 kilograms (440 lb)+ range. Most large crematoria have a small cremator installed for the cremation of fetal and infant remains.
In the U.S., a body ready to be cremated must be placed in a container for cremation, which can be a simple corrugated cardboard box or a wooden casket. Most casket manufacturers provide a line of caskets specially built for cremation. Another option is a cardboard box that fits inside a wooden shell designed to look like a traditional casket. After the funeral service, the interior box is removed from the shell before cremation, permitting the shell to be reused. Funeral homes may also offer rental caskets, which are traditional caskets used only for the duration of the services, after which the body is transferred to another container for cremation. Rental caskets are sometimes designed with removable beds and liners, which are replaced after each use.
In the UK, the body is not removed from the coffin and is not placed into a container as described above. The body is cremated with the coffin, which is why all UK coffins that are to be used for cremation must be made of combustible material. The Code of Cremation Practice forbids the opening of the coffin once it has arrived at the crematorium, and rules stipulate it must be cremated within 72 hours of the funeral service. Thus, in the UK, bodies are cremated in the same coffin as they are placed in at the undertaker's although the regulations allow the use of an approved 'cover' during the funeral service. It is recommended that jewelry be removed before the coffin is sealed for this reason. After the cremation process has been completed, the remains are passed through a magnetic field to remove any metal, which will be interred elsewhere in the crematorium grounds, or increasingly, recycled. The ashes are then given to relatives or loved ones or scattered in the Crematorium grounds where facilities exist.
In Australia, the deceased are cremated in a coffin supplied by the undertaker. Reusable or cardboard coffins are becoming popular, with several manufacturers now supplying them. If cost is an issue, a plain, particle-board coffin (known in the trade as a "chippie") will be offered. Handles (if fitted) are plastic and approved for use in a cremator. Coffins vary from natural cardboard or unfinished particle board (covered with a velvet pall if there is a service) to solid timber; most are veneered particle board.
Cremations can be "delivery only," with no preceding chapel service at the crematorium (although a church service may have been held) or preceded by a service in one of the crematorium chapels. Delivery-only allows crematoria to schedule cremations to make best use of the cremators, perhaps by holding the body overnight in a refrigerator. As a result, a lower fee is applicable. Delivery-only may be referred to in industry jargon as "west chapel service."
Burning and ashes collection
The box containing the body is placed in the retort and incinerated at a temperature of 760° to 1150°C (1400° to 2100°F). During the cremation process, a large part of the body (especially the organs) and other soft tissue are vaporized and oxidized by the intense heat; gases released are discharged through the exhaust system. The process usually takes 90 minutes to two hours, with larger bodies taking longer time.
What remains after cremation are dry bone fragments. Their color is usually light gray.
Jewellery, such as wristwatches and rings, is ordinarily removed before cremation, and returned to the family. The only non-natural item required to be removed is a pacemaker, because it could explode and damage the cremator; the mercury contained in a pacemaker's batteries also poses an unacceptable risk of air pollution. In the United Kingdom, and possibly other countries, the undertaker is required to remove pacemakers prior to delivering the body to the crematorium, and sign a declaration stating that any pacemaker has been removed.
After the incineration is completed, the bone fragments are swept out of the retort and pulverized by a machine called a cremulator to process them into "ashes" or "cremated remains". The end result are sand size grains, though the size varies depending on the cremulator used. There are various types of cremulators the rotating ones, grinders, and heavy metal balls on older models. The grinding process typically takes about 20 minutes.
In a Japanese funeral and in Taiwan, the bones are not pulverized unless requested beforehand. When not pulverized the bones are collected by the family and stored as one might do with ashes.
The appearance of cremated remains after grinding is one of the reasons they are called ashes, although a non-technical term sometimes used is "cremains", a portmanyeau of "cremated" and "remains". (The Cremation Association of North America prefers the word "cremains" to not be used for referring to "human cremated remains." The reason given is that "cremains" is thought to have less connection with the deceased, whereas a loved one's "cremated remains" has a more identifiable human connection.)
After final grinding, the ashes are placed in a container, which can be anything from a simple cardboard box to a decorative urn. The default container used by most crematoriums, when nothing more expensive has been selected, is almost always a hinged snap-locking box of plastic.
An unavoidable consequence of cremation is that a tiny residue of bodily remains is left in the chamber after cremation and mixes with subsequent cremations.
Ash weight and composition
Cremated remains are mostly dry calcium phosphates with some minor minerals, such as salts of sodium and potassium. Sulfur and most carbon is driven off as oxidized gases during the process, although a relatively small amount of carbon as carbonate may remain.
The ash remaining represents very roughly 3.5% of the body's original mass (2.5% in children). Because the weight of dry bone fragments is so closely connected to skeletal mass, their weight varies greatly from person to person. Because many changes in body composition (such as fat and muscle loss or gain) do not affect the weight of cremated remains, their weight can be more closely predicted from the person's height and sex than from their simple weight.
Ashes of adults can be said to weigh from 4 pounds (1.8 kg) to 6 pounds (2.7 kg), but the first figure is roughly the figure for women and the second for men. The mean weight of adult cremated remains in a Florida, U.S. sample was 5.3 lb (approx. 2.4 kg) for adults (range 2 to 8 lb or 0.91 to 3.6 kg). This was found to be distributed bimodally according to sex, with the mean being 6 pounds (2.7 kg) for men (range 4 to 8 lb or 1.8 to 3.6 kg) and 4 pounds (1.8 kg) for women (range 2 to 6 lb or 0.91 to 2.7 kg). In this sample, generally all adult cremated remains over 6 pounds (2.7 kg) were from males, and those under 4 pounds (1.8 kg) were from females.
Not all that remains is bone. There may be melted metal lumps from missed jewellery; casket furniture; dental fillings; and surgical implants, such as hip replacements. Large items such as titanium hip replacements (which tarnish but do not melt) or casket hinges are usually removed before grinding, as they may damage the grinder. (If they are missed at first, they must ultimately be removed before grinding is complete, as items such as titanium joint replacements are far too durable to be ground). Implants may be returned to the family, but are more commonly sold as ferrous/non-ferrous scrap metal. After grinding, smaller bits of metal such as tooth fillings, and rings (commonly known as gleanings) are sieved out and may be later interred in common, consecrated ground in a remote area of the cemetery. They may also be sold as precious metal scrap.
Reasons for choosing cremation
Apart from religious reasons (discussed below), some people find they prefer cremation to traditional burial for personal reasons. The thought of a long, slow decomposition process is unappealing to some; many people find that they prefer cremation because it disposes of the body immediately.
Other people view cremation as a way of simplifying their funeral process. These people view a traditional burial as an unneeded complication of their funeral process, and thus choose cremation to make their services as simple as possible.
The cost factor tends to make cremation attractive. Generally speaking, cremation is cheaper than traditional burial services, especially if direct cremation is chosen, in which the body is cremated as soon as legally possible without any sort of services.
Cremated remains can be scattered or buried. Cremation plots or columbarium niches are usually cheaper than a traditional burial plot or mausoleum crypt, and require less space. Some religions, such as Roman Catholicism, require the burial or entombment of cremated remains, but burial of cremated remains may often be accomplished in the burial plot of another person, such as a family member, without any additional cost. It is also very common to scatter the remains in a place which was liked by the deceased such as the sea, a river, a beach or a park, following their last will.
Cremation might be preferable for envirnomental reasons. Burial is a known source of certain environmental contaminants, with the coffin itself being the major contaminant. Another concern is contamination from radioisotopes that have entered the body before death or burial, although cremation does not seem to be advantageous. For example, one possible source of isotopes is eadiation therapy, although no accumulation of radiation occurs in the most common type of radiation therapy involving high energy photons. However, cremation has no effect on radioisotopes other than to return them to the environment more rapidly (beginning with some spread into the air).
Yet another environmental concern, of sorts, is that traditional burial takes up a great deal of space. In a traditional burial, the body is buried in a casket made from a variety of materials. In America, the casket is often placed inside a concrete vault or liner before burial in the ground. While individually this may not take much room, combined with other burials, it can over time cause serious space concerns. Many cemeteries, particularly in Japan and Europe as well as those in larger cities, have run out of permanent space. In Tokyo, for example, traditional burial plots are extremely scarce and expensive, and in London, a space crisis led Harriet Harmen to propose reopening old graves for "double-decker" burials.
Cremation dates to at least 20,000 years ago in the archaeological record with the Mungo Lady, the remains of a partly cremated body found at Mungo Lake, Australia.
Alternative death rituals emphasizing one method of disposal of a body—inhumation (burial), cremation, and exposure—have gone through periods of preference throughout history.
In the Middle East and Europe, both burial and cremation are evident in the archaeological record in the Neolithic. Cultural groups had their own preference and prohibitions. The ancient Egyptians developed an intricate transmigration of soul theology, which prohibited cremation, and this was adopted widely among other Semitic peoples. The Babylonians, according to Herodotus, embalmed their dead. Early Persians practiced cremation, but this became prohibited during the Zoroastrian Period. Phoenicians practiced both cremation and burial. From the Cycladic civilisation in 3000 BC until the Sub-Mycenaean era in 1200–1100 B.C., Greeks practiced inhumation. Cremation appearing around the 12th century B.C. constitutes a new practice of burial and is probably an influence from Minor Asia. Until the Christian era, when the inhumation becomes again the only burial practice, both combustion and inhumation had been practiced depending on the era, and area. Romans practiced both, with cremation generally associated with military honors.
In Europe, there are traces of cremation dating to the Early Bronze Age (ca. 2000 B.C.) in the Pannonian Plain and along the middle Danube. The custom becomes dominant throughout Bronze Age Europe with the Urnfield culture (from ca. 1300 B.C.). In the Iron Age, inhumation becomes again more common, but cremation persisted in the Villanovan culture and elsewhere. Homer's account of Patroclus' burial describes cremation with subsequent burial in a tumulus similar to Urnfield burials, qualifying as the earliest description of cremation rites. This is mostly an anachronism, as during Mycenaean times burial was generally preferred, and Homer may have been reflecting more common use of cremation in the period in which the Iliad was written centuries later.
Criticism of burial rites is a common aspersion in competing religions and cultures, and one is the association of cremation with fire sacrifice or human sacrifice.
Hinduism and Jainism are notable for not only allowing but prescribing cremation. Cremation in India is first attested in the Cemetery H culture (from ca. 1900 B.C.), considered the formative stage of Vedic civilization. The Rigveda contains a reference to the emerging practice, in RV 10.15.14, where the forefathers "both cremated (agnidagdhá-) and uncremated (ánagnidagdha-)" are invoked.
Cremation remained common, but not universal, in both Ancient Greece and Ancient Rome. According to Cicero, in Rome, inhumation was considered the more archaic rite, while the most honoured citizens were most typically cremated—especially upper classes and members of imperial families.
Christianity frowned upon cremation, both influenced by the tenets of Judaism, and in an attempt to abolish Graeco-Roman pagan rituals. By the 5th century, the practice of cremation had practically disappeared from Europe.
In early Roman Britain, cremation was usual but diminished by the fourth century. It then reappeared in the fifth and sixth centuries during the migration era, when sacrificed animals were sometimes included with the human bodies on the pyre, and the deceased were dressed in costume and with ornaments for the burning. That custom was also very widespread among the Germanic peoples of the northern continental lands from which the Anglo-Saxon migrants are supposed to have been derived, during the same period. These ashes were usually thereafter deposited in a vessel of clay or bronze in an "urn cemetery." The custom again died out with the Christian conversion among the Anglo-Saxons or Early English during the seventh century, when inhumation of the corpse became general.
In the Middle Ages
Throughout parts of Europe, cremation was forbidden by law, and even punishable by death if combined with Heathen rites. Cremation was sometimes used by authorities as part of punishment for heretics, and this did not only include burning at the stake. For example, the body of John Wycliff was exhumed years after his death and cremated, with the ashes thrown in a river, explicitly as a posthumous punishment for his denial of the Roman Catholic doctrine of transubstantiation. On the other hand, mass cremations were often performed out of fear of contagious diseases, such as after a battle, pestilence, or famine. Retributory cremation continued into modern times. For example, after World War II, the bodies of the 12 men convicted of crimes against humanity at the Nuremberg Trials were not returned to their families, but were instead cremated, then disposed of at a secret location as a specific part of a legal process intended to deny their use as a location for any sort of memorial. In Japan, however, erection of a memorial building for many executed war criminals, who were also cremated, was allowed for their remains.
The modern era
In 1873, Paduan Professor Brunetti presented a cremation chamber at the Vienna Exposition. In Britain, the movement found the support of Queen Victoria's surgeon, Sir Henry Thompson, who together with colleagues founded the Cremation Society of England in 1874. The first crematoria in Europe were built in 1878 in Woking, England and Gotha, Germany, the first in North America in 1876 by Dr. Francis Julius LeMoyne in Washington, Pennsylvania. The second cremation in the United States was that of Charles F. Winslow in Salt Lake City, Utah on July 31, 1877. The first cremation in Britain took place on 26 March 1886 at Woking.
Cremation was declared as legal in England and Wales when Dr. William Price was unsuccessfully prosecuted for cremating his son; formal legislation followed later with the passing of the Cremation Act of 1902 (this Act did not extend to Ireland), which imposed procedural requirements before a cremation could occur and restricted the practice to authorised places. In 1885 the first official cremation took place at Woking. Ten cremations then took place in 1886. In 1892 a crematorium opened in Manchester, followed by one in Glasgow in 1895 and one in Liverpool in 1896.
Some of the various Protestant churches came to accept cremation, with the rationale being, "God can resurrect a bowl of ashes just as conveniently as he can resurrect a bowl of dust." The 1908 Catholic Encyclopedia was critical about these efforts, referring to them as a "sinister movement" and associating them with Freemasonry, although it said that "there is nothing directly opposed to any dogma of the Church in the practice of cremation." In 1963, Pope Paul VI lifted the ban on cremation, and in 1966 allowed Catholic priests to officiate at cremation ceremonies.
Australia also started to establish modern cremation movements and societies. Australians had their first purpose-built modern crematorium and chapel in the West Terrace Cemetery in the South Australian capital of Adelaide in 1901. This small building, resembling the buildings at Woking, remained largely unchanged from its 19th century style and was in full operation until the late 1950s. The oldest operating crematorium in Australia is at Rookwood Cemetery, in Sydney. It opened in 1925.
In the Netherlands, the foundation of the Association for Optional Cremation in 1874 ushered in a long debate about the merits and demerits of cremation. Laws against cremation were challenged and invalidated in 1915 (two years after the construction of the first crematorium in the Netherlands), though cremation did not become legally recognised until 1955.
The technology in crematories has improved over the years. Dr. Steve Looker owner and CEO of B&L Cremation Systems Inc. invented a new system called the "Hot Hearth" in the early 1980s. This systems allows the hearth or the base of the machine to heat up from the hot gases running underneath the hearth. This allows the machine to maintain higher temperature which saves gas and reduces the impact on the environment. Dr. Looker also introduced many other new ideas to the cremation industry. He came up with the design for a separate remains removal door, located on the side of the unit. This enables the operator to push the remains to the rear of the chamber and remove the remains there. By doing this the heat loss is reduced in the machine and therefore saves energy. Crematories used to run on timers (some still do) and one would have to figure out the weight of the body, then figure out how long the body has to be cremated and then set multiple timers. Now there are crematories that are fully automated with PLC (Programmable logic controller) touchscreens, where the weight and the name of the deceased have to be entered before a 'start'-button is pressed.
Source - http://en.wikipedia.org/wiki/Cremation