Alkaline Hydrolysis
There are different approaches to alkaline hydrolysis which include both pressurised machines that use high temperatures, and unpressurised machines operating at lower or atmospheric temperatures. In the USA, two main companies provide this technology—Bio-Response and Resomation. Although it is relatively new, it is a proven, operational technology, and represents a disruptive innovation to the funeral industry.
Alkaline Hydrolysis is known by several names, including flameless cremation, water cremation, Resomation, and Aquamation. In the USA it is currently legal in over 20 states.
In the Alkaline Hydrolysis (AH) process, a shrouded (or naked) body is placed in a chamber filled with a solution of water and alkali. During the process, organic tissues break down, leaving behind the bones and any artificial materials—such as titanium hips or knees. The bones are then processed into a fine powder, similar in appearance to flame cremation ashes or cremains, and returned to the family. These remains can be kept, scattered, placed in a columbarium, or buried.
Only natural, protein-based fibres and materials are used for shrouding and body preparation, as the body is best treated as naturally as possible. AH produces no atmospheric emissions, making it a cleaner alternative to flame cremation. It is designed to replicate above ground what natural burial achieves underground, and is already available in some parts of Australia.
Alkaline hydrolysis has been used for decades around the world to dispose of large farm animals, with the resulting liquid often repurposed for irrigation or agricultural use. When applied to humans, the process is essentially the same. However, instead of being reused on farmland, the liquid is treated to a safe pH level and then returned to the water cycle through standard wastewater systems.
The solution used in this process is approximately 5% alkali and 95% water. In 2020, the Dutch government commissioned a study (Dutch government study) to examine the safety of the resulting effluent. The report concluded that the water contains no DNA and nothing harmful, making it completely safe for release into the water treatment system. Additionally, the study found that alkaline hydrolysis meets the key principles required for body disposition: safety, dignity, and sustainability.
In addition to its economic and environmental impact, when compared to flame cremation, alkaline hydrolysis offers a range of benefits. A coffin is not required, only natural mortuary techniques are used, and synthetic or plastic materials cannot be part of the process.
What does this mean in practice? As sometimes occurs in conventional preparation, AH does not require the body to be stitched, packed with cotton wool, or fitted with plastic eye caps. In some systems, metal components, as well as titanium and ceramic joints remain intact and can be retrieved at the end, pacemakers also do not need to be removed.
Alkaline hydrolysis works most effectively when the person has been prepared as naturally as possible. However AH is still possible for an embalmed body. If a body has been embalmed, particularly if strong cavity fluids have been used which slow decomposition down, the process may need to be run twice.
The economic benefits of Alkaline hydrolysis are notable, as the process is relatively inexpensive and is less labour intensive than traditional methods. It also eliminates the need for a coffin, reducing costs for families. Overall, it offers a more affordable and gentle alternative to flame cremation with less invasive body preparation.
In addition, the process has clear environmental benefits as it consumes less energy than flame cremation, produces no atmospheric pollution, eliminates harmful toxins, and conserves valuable natural resources. It significantly reduces carbon emissions, making it a much more sustainable option.