Please note: Alkaline hydrolysis is the scientific term for this method of disposition.
Water cremation is growing in popularity across Canada and other parts of the world. However, the final disposition process is still relatively new to the funeral industry, and many people are unfamiliar with what it entails. This article provides insight into water cremation and answers basic questions people have about the process.
Alkaline hydrolysis, also known as water cremation, is a water-based form of final disposition that speeds up physiological changes after death by exposing remains to pressure, heat, water, and alkali (potassium hydroxide). This process is an accelerated version of the reaction that occurs when a body is buried in the ground. Like flame cremation, water cremation produces ashes without using flames and extreme heat. It also produces about 20 to 30 per cent more ashes.
The scientific name for water cremation is alkaline hydrolysis. You will also see it referenced using the following synonyms:
Water cremation was developed by a farmer named Amos Herbert Hanson in 1888 to turn animal carcasses into fertilizer. It was then adapted for lab use to dispose of contaminated animal bodies.
In the 1990s, water cremation was used to dispose of research cadavers at medical schools and was the predominant use of this technology for several years.
It was in the early 2000s that water cremation became an option for non-cadaver human remains. Minnesota was the first state to legalize it in 2003, and Saskatchewan followed suit in 2012. Since then, the process has been approved and legalized in many parts of North America.
Water cremation is available for human remains in five Canadian provinces and territories and 19 states in the U.S., with pending legalization in several other parts of North America.
The technology is also permitted for pets in all U.S. states and Canadian provinces and territories.
Learn more about the legal status of water cremation in Canada and the United States.
The water process starts with placing the body in a stainless steel vessel. The vessel is filled with water and alkali (potassium hydroxide), an odourless, off-white flaky, or lumpy solid. The ratio of the alkali solution is typically 95 per cent water to five per cent alkali, but it may vary depending on body characteristics (e.g., height).
The vessel is exposed to high temperatures (200 to 320 F / 93 to 160 C) and agitation to prevent boiling and help break down organic material. The solution reduces compounds in the body to organic components (e.g., fats are reduced to salts), which are dissolved into the water.
The process leaves behind two by-products: bone fragments and a sterile, green-brown liquid, containing salts, amino acids, sugars, peptides, and water.
Next, the liquid is released from the vessel as wastewater, and the remains and equipment are rinsed with fresh water. Metals are sterilized and removed using a magnet or sieve.
Finally, the bone fragments are reduced to a fine, white, or tan powder, placed in an urn, and returned to the family. The entire process typically takes between 6 to 20 hours.
Metal implants (e.g., pacemakers) are not removed before water cremation unless legally required by funeral regulatory bodies. Unlike flame cremation, implants are not destroyed and do not pose safety risks to hydrolysis facility workers. However, clothing and personal items that are not protein based (e.g., wool) must be removed.
Implants are left in the body during water cremation. Once the process is completed, they are cleaned, sterilized, and removed. The leftover metals are recycled or donated.
The cost of water cremation varies depending on the funeral home and included services. Direct or basic services are typically the cheapest because they forgo expensive services such as a viewing, committal, gravesite services, etc.
Water cremation services can vary anywhere from $1,000 to over $10,000. However, it typically ranges from $2000 to $3000+.
Water and flame cremation have similarities but use different methods to produce ashes. The main differences are in the process and preparation, the ashes, environmental impact, cost, and availability. See more information here.
As the names suggest, flame cremation reduces remains using flames and extreme heat, while water cremation is a water-based final disposition method that uses alkaline hydrolysis to produce ashes.
The flame cremation process typically takes up to three hours, depending on the size and weight of the body and the type of casket or container used. Meanwhile, water cremation typically takes between 6 to 20 hours.
Body preparation is also less labour-intensive for water cremation than flame cremation since medical implants do not need to be removed beforehand. However, clothing and personal items that are not protein-based must be.
Flame cremation ashes typically have a 1:1 ratio between the weight of the deceased person and the volume of ashes produced in cubic inches. For example, if a person weighs 120 lbs, approximately 120 cubic inches of ashes will be produced from flame cremation. The ashes will also be grey or brown with a coarse consistency resembling sand.
However, aquamation produces approximately 20 to 30 per cent more ashes than flame cremation. Therefore, someone weighing 120 lbs would produce about 144 to 156 cubic inches of ashes. The remains are also a tan or white colour with a smooth consistency.
Large amounts of energy are used to reach the temperatures needed for flame cremation (760 to 980 Celsius / 1,400 to 1796 F). This contrasts with the much lower temperatures required for water cremation (160 Celsius / 320 F). Water cremation is more energy efficient, using over 80 per cent less than flame cremation.
Flame cremation also emits greenhouse gases such as carbon monoxide, embalming chemicals (e.g., formaldehyde), mercury, etc. However, water cremation has no direct emissions of harmful gases. The main byproduct is a sterile liquid that can be disposed of as wastewater. Water cremation also uses less water than a single household uses in one day (source: USGS.gov).
Water cremation is typically more expensive than flame cremation, but the prices are often not drastically different. On average, water cremation packages range from $2000 to $3000+, while flame cremation packages ranges from $800 to over $3000.
Flame cremation is widely available across North America, but water cremation is only available in areas that have legalized the alkaline hydrolysis process for use on human remains. Additionally, even in areas where water cremation is legal, funeral providers that offer the service may be limited.
In Canada, water cremation is legal in five Canadian provinces and territories - Saskatchewan, Ontario, Quebec, Newfoundland and Labrador, and Northwest Territories.
A handful of funeral providers in Saskatchewan, Ontario, and Quebec provide water cremation services. However, there are no providers in the Northwest Territories, and there is only one location where it is available in Newfoundland and Labrador.
In the U.S., water cremation is legal in these states.
Here are additional resources that will help you better understand water cremation and alkaline hydrolysis:
Have a question about water cremation? Email us at support@eirene.ca.
Eirene offers water cremation in select provinces in Canada. See our service locations.