Water cremation. Alkaline hydrolysis (also called biocremation, resomation, flameless cremation, aquamation or water cremation) is a process for the disposal of human and pet remains using lye and heat; it is alternative to burial, cremation, or sky burial.

Process
The process is based on alkaline hydrolysis: the body is placed in a pressure vessel which is then filled with a mixture of water and potassium hydroxide, and heated to a temperature of around  at an elevated pressure which precludes boiling. The body is efficiently broken down into its chemical components, (completely disintegrating its DNA), a process which takes approximately four to six hours. Also, lower temperatures () and pressures may be used such that the process takes a leisurely  14 to 16 hours. At the start, the mixture is very alkaline, with a pH level of approximately 14; this drops to approximately 11 by the end, but the exact value depends on the total operation time and the amount of fat in the body.

The result is a quantity of green-brown tinted liquid (containing amino acids, peptides, sugars and salts) and soft, porous white bone remains (calcium phosphate) easily crushed in the hand (although a cremulator is more commonly used) to form a white-colored dust. The "ash" can then be returned to the next of kin of the deceased. The liquid is disposed of either through the sanitary sewer system, or through some other method, including use in a garden or green space. To dispose of  of biomass, approximately  of water are used, resulting in  of effluent, which carries a dried weight (inorganic and mineral
content) of  (approximately 2% of original weight).

This alkaline hydrolysis process has been championed by a number of ecological campaigning groups, for using 90 kWh of electricity, one-quarter the energy of flame-based cremation, and producing less carbon dioxide and pollutants. It is being presented as an alternative option at some British crematorium sites. , about 1,000 people had chosen this method for the disposal of their remains in the United States. The operating cost of materials, maintenance, and labor associated with the disposal of  of remains was estimated at $116.40, excluding the capital investment cost of equipment.

Alkaline hydrolysis has also been adopted by the pet and animal industry. A handful of companies in North America offer the procedure as an alternative to pet cremation. Alkaline hydrolysis is also used in the agricultural industry to sterilize animal carcasses that may pose a health hazard, because the process inactivates viruses, bacteria, and prions that cause transmissible spongiform encephalopathy.

History
The process was  patented by Amos Herbert Hobson in 1888 as a method to process animal carcasses into plant food. In 2005, Bio-Response Solutions designed, sold, and installed the first single cadaver alkaline hydrolysis system at the Mayo Clinic, where it was still in use as of 2019. In 2007, a Scottish biochemist, Sandy Sullivan, started a company making the machines, and calling the process (and company) Resomation.

Religious views

In Christian countries and cultures, cremation has historically been discouraged and viewed as a desecration of God's image, and as interference with the resurrection of the dead taught in scripture. It is now acceptable to some denominations. Desmond Tutu, former Anglican Archbishop of Cape Town, was aquamated, per his wish. The Eastern Orthodox Church does not allow cremation.

The Roman Catholic Church allows cremation of bodies as long as it is not done in denial of the beliefs in the sacredness of the human body or the resurrection of the dead. In 2008, Renée Mirkes published the first Catholic moral analysis of alkaline hydrolysis. He argued that it is morally neutral and may be an alternative to burial on similar grounds to cremation. However, the Catholic Church in the United States does not approve of alkaline hydrolysis as a method of final disposal of human remains. In 2011, Donald Cardinal Wuerl, Archbishop of Washington and then chairman of the Committee on Doctrine of the United States Conference of Catholic Bishops (USCCB), determined it "unnecessarily disrespectful of the human body." The Archdiocese of St. Louis explained that it was considered this way because the Church took concern with the final disposal of the liquid solution, which is typically to the sewer system. This was considered disrespectful of the sanctity of the human body. Additionally, when alkaline hydrolysis was proposed in New York state in 2012, the New York State Catholic Conference condemned the practice, stating that hydrolysis does not show sufficient respect for the teaching of the intrinsic dignity of the human body.

Judaism forbids cremation as it is not in line with the religion’s teachings of respect and dignity for humans, who are believed by the religion to be created in God’s image. Islam also forbids cremation of the deceased. Both religions are likely to reject alkaline hydrolysis as they believe that the body must be laid to rest through burial in order to prepare for the afterlife. The Baháʼí Faith, like other Abrahamic religions, discourages cremation of the deceased. The human body is seen as having to be treated with respect, and merely wrapped in a shroud before burial no further than an hour from the place of death.

Sikhism, Hinduism, and Buddhism each place theological emphasis on the complete immolation of the corpse.

Native Hawaiians consider aquamation a way to approximate their traditional burial ritual, which involves removing the bones (iwi) cleanly from the flesh using a beachside underground oven (imu), wrapping the bones, and hiding them. The use of an imu on human bodies is no longer allowed, but aquamation may offer an alternative as it produces similarly clean bones.

Legal status

Australia 
Aquamation based in New South Wales is the only company to provide alkaline hydrolysis in Australia, with the remains being used as fertilizer on plantation forests, due to difficulty with obtaining permits from Sydney Water.

New Zealand 
Debbie Richardson of Water Cremation Aotearoa  has been an advocate for bringing the service to New Zealand (Aotearoa). Water cremation services will be offered in Christchurch by Bell, Lamb and Trotter.

Belgium

Flanders 
The Flemish minister of Interior Administration Bart Somers asked in September 2021 the opinion of an advisory bioethics committee on resomation. The advice, received in November 2021, saw no objections.

Canada
Saskatchewan approved the process in 2012, becoming the first province to do so. Quebec and Ontario have also legalized the process.
A funeral home in Granby, Quebec, was the first in the province to receive an alkaline hydrolysis machine.

Ireland 
In 2023, water cremation became available in Ireland, making it the first country in Europe to offer this form of burial.

When the process is complete, the remaining water undergoes further treatment to ensure that it is completely sterile. Analysis is then completed to ensure Water Authority standards are met. At this stage, the water can be recycled back to the Local Authority water treatment plant.

Mexico 
Since 2019, Grupo Gayosso offers alkaline hydrolysis in Baja California.

The Netherlands 

In May 2020, the Health Council of the Netherlands issued an advisory report on the admissibility of new techniques of disposing of the dead. The Council proposed a framework to assess alkaline hydrolysis. It concluded that alkaline hydrolysis is safe, dignified and sustainable. In addition to alkaline hydrolysis, the council also considered human composting as a technique to dispose bodies yet concluded that too little is known about composting and hence it cannot be assessed whether this technique fulfills the conditions. Taking into account the council's recommendations, the Ministry of the Interior and Kingdom Relations prepared a law proposal to amend the Corpse Disposal Act. Once the proposed law has been submitted to the Parliament, the democratic process to admit alkaline hydrolysis as body disposal technique can be commenced.

South Africa
In November 2019, Avbob introduced aquamation in South Africa, following the mutual assurance society's recent introduction of the alkaline hydrolysis process at its Maitland agency in Cape Town. Aquamation has been legal in South Africa since then. Following his death in December 2021 the body of Archbishop Desmond Tutu was aquamated.

United Kingdom
A public crematorium operated by Sandwell Metropolitan Borough Council at Rowley Regis, central England, was the first to receive planning permission to offer the process but in March 2017, the local water utility, Severn Trent Water, refused the council's application for a "trade effluent permit" because there was no water industry standard regulating the disposal of liquefied human remains into sewers.

In July 2023, the BBC reported that “[w]ater cremation is set to be made available for the first time in the UK.”

United States
Alkaline hydrolysis as a method of final disposition of human remains is legal in 24 states . Legislation is pending in New Jersey, New York, Ohio, Pennsylvania, and Virginia. The process was legal in New Hampshire for several years but amid opposition by religious lobby groups it was banned in 2008 and a proposal to legalize it was rejected in 2013.
Alkaline hydrolysis has been used for cadavers donated for research at the University of Florida since the mid-1990s and at the Mayo Clinic since 2005. UCLA uses the process to dispose of donor bodies.

See also
 Burial
 Promession
 Human composting

References

Further reading
 New in mortuary science: Dissolving bodies with lye – ABC News
 New body 'liquefaction' unit unveiled in Florida funeral home – BBC News

Death customs
Biodegradation
Funeral-related industry
Legal aspects of death
Waste management