Alkaline Hydrolysis
Alkaline hydrolysis, also called water cremation or resomation, uses heated water and alkali to accelerate the body's natural decomposition — a lower-emission alternative to flame cremation.
Overview
Alkaline hydrolysis is a body disposition method that uses a heated solution of water and potassium or sodium hydroxide inside a pressurized vessel to break the body down to its basic chemical components. It is also marketed under names such as water cremation, resomation, aquamation, or bio-cremation, though the underlying chemistry is the same.
The process has been used for decades in veterinary and medical research settings before being adapted and legalized for human remains, and it is chemically related to processes that occur naturally, but greatly accelerated.
How It Works
The body is placed in a stainless-steel vessel filled with a mixture of water and alkali. The vessel is heated to between roughly 200–300°F (depending on whether a high-pressure or low-pressure system is used) for several hours. This breaks down soft tissue at the molecular level, leaving behind only bone fragments, which — as with flame cremation — are then processed into a fine powder and returned to the family.
The liquid byproduct, composed of amino acids, peptides, sugars, and salts, is sterile and is typically released into the municipal wastewater system in accordance with local regulations, similar to how other approved effluents are managed.
Sustainability & Environmental Impact
Alkaline hydrolysis providers and independent researchers generally report substantially lower energy use and greenhouse gas emissions compared to flame cremation, since it does not require burning fossil fuels to reach cremation temperatures and does not release mercury from dental amalgam or other combustion byproducts into the air.
Legal Status & Availability
Alkaline hydrolysis is legal for human remains in a growing number of U.S. states — roughly half as of recent counts — as well as in Canada, the UK (in limited capacity), and parts of Europe and Australia, though availability of licensed facilities lags behind legal authorization in many areas. Regulatory frameworks continue to evolve, so confirm current legal status and facility availability in your specific location.
Laws governing body disposition vary by country, state/province, and sometimes county. Always verify current regulations with a local funeral authority, cemetery board, or attorney before making decisions.
Considerations
Because facility availability remains limited even in states where the process is legal, families may need to work with a funeral home that partners with a licensed provider in another region. Cost is generally comparable to flame cremation. Some families are drawn to the process specifically for its lower environmental footprint; others prefer the more familiar imagery of flame cremation — both are personal choices worth discussing openly with a funeral provider.
Frequently Asked Questions
Is alkaline hydrolysis the same as "water cremation"?
Yes — water cremation, resomation, and aquamation are all common marketing names for the alkaline hydrolysis process.
Do families receive remains back, like with cremation?
Yes. Bone fragments are processed into a fine powder, similar in appearance to cremated remains from flame cremation, and returned to the family.
Is the process safe and regulated?
In jurisdictions where it is legal, the process is regulated by state or provincial health and funeral authorities, including standards for the treatment of the liquid byproduct.
Why isn't alkaline hydrolysis available everywhere?
Legalization and facility buildout have progressed unevenly, often due to the cost of specialized equipment and the pace of state-by-state legislative approval.