Alkaline Hydrolysis Process: Cycles, Liquid Byproduct, and Costs

The alkaline hydrolysis process reduces a body to a sterile liquid and bone fragments by immersing it in heated water mixed with a strong alkali inside a sealed pressure vessel. The reaction mimics what happens during natural burial decomposition, but finishes in hours rather than years. Roughly 28 states currently allow it for human disposition, though the terminology on paperwork varies from one state to the next.¹

What Happens Inside the Chamber

The body is placed inside a stainless steel pressure vessel, sometimes called a resomator or bio-cremation chamber. These vessels are built to the Boiler and Pressure Vessel Code published by the American Society of Mechanical Engineers, which sets the engineering standards for safe operation under high pressure and temperature.² Once sealed, the chamber fills with a solution of water and either potassium hydroxide or sodium hydroxide. Automated systems weigh the remains at the start of the cycle and calculate the exact volume of water and chemical needed.

As the temperature climbs, the alkaline solution attacks the chemical bonds in proteins, fats, and nucleic acids, breaking them down into their basic molecular components. Soft tissue dissolves into the liquid. The mineral structure of the bones stays intact. The fluid circulates continuously throughout the cycle, keeping temperature and chemical concentration even across the body and stripping organic material from the skeleton. By the end of the run, everything except bone fragments and any non-organic implants has been reduced to liquid.

The chamber itself holds about 100 gallons of solution, though a full cycle including rinsing and flushing uses closer to 300 gallons of water.¹

High-Temperature and Low-Temperature Cycles

Two variants of the process exist, and the choice determines how long a cycle takes.

High-temperature units run at around 302°F (150°C) under roughly 4 bar of pressure. The pressurized environment keeps the solution from boiling, which would disrupt the reaction. A cycle finishes in about 3.5 to 6 hours, and a machine can complete two or more cycles per day.³ Most commercial funeral service providers use high-temperature equipment because throughput matters when they’re serving multiple families.

Low-temperature units run at roughly 200–208°F (93–98°C) at normal atmospheric pressure, with no pressurization at all. The cycle takes 14 to 18 hours, which limits the machine to one or two runs per day.³ These systems are more common at smaller operations and pet facilities where speed matters less and the simpler engineering reduces maintenance.

What the Liquid Byproduct Is

When the cycle finishes, the fluid remaining in the chamber is a sterile, tea-colored liquid made up of amino acids, peptides, sugars, and salts extracted from the dissolved tissues. The combination of heat, pressure, and extreme alkalinity destroys all pathogens, bacteria, and viruses, including prions, the misfolded proteins responsible for diseases like mad cow and scrapie that survive conventional sterilization. A peer-reviewed study found that alkaline hydrolysis fully inactivated prion proteins in laboratory animals, with no treated subjects developing the disease.⁴ The process also breaks down DNA completely, so no identifiable genetic material remains in the effluent.

The liquid has a pH between 11 and 13, which makes it strongly alkaline. Before it enters a municipal sewer system, it must meet the local wastewater authority’s requirements for temperature and pH. Some municipalities accept the effluent at its existing pH. Others require the facility to lower it first using carbon dioxide or acid-based neutralizing agents. Operators work under industrial discharge permits and face periodic testing to prove compliance.¹

What the Family Receives

After the liquid drains, the only solid material left in the chamber is the skeletal structure, sometimes called bone shadows. The fragments are calcium phosphate and extremely brittle, because the alkaline solution has dissolved the collagen that normally gives bone its flexibility. An operator rinses them with fresh water to remove any residual alkaline solution, then moves them to a drying system.

Once dry, the fragments go through a mechanical pulverization that reduces them to a fine white or off-white powder. The result looks similar to the ashes from flame cremation, but alkaline hydrolysis yields about 32% more material by volume because the bones have not been oxidized by fire.¹ Families may need a slightly larger urn. The powder is placed in a container and returned, and can be scattered, buried, or stored the same way as traditional cremation ashes.

How Medical Implants Are Handled

One practical difference from flame cremation is the way the process handles medical devices. Pacemakers must be surgically removed before flame cremation because their lithium batteries can explode at high temperatures. They do not need to be removed before alkaline hydrolysis, except where a specific state law requires it.¹ Joint replacements, surgical pins, dental work, and other metal hardware come through the cycle intact and are collected from the chamber afterward. Facilities typically sort and recycle this material through medical waste channels.

Where It Is Legal and What It Costs

Alkaline hydrolysis is not available everywhere. Approximately 28 states have passed laws or adopted regulatory interpretations authorizing it for human remains, with legalization dates ranging from 2003 in Minnesota to 2023 in Arizona. A few states explicitly prohibit the practice, and many others have no law addressing it at all, which effectively prevents licensed funeral homes there from offering the service. Terminology on death certificates also varies: the method of disposition may be recorded as “alkaline hydrolysis,” “cremation,” “chemical disposition,” or “dissolution,” depending on state law.¹ A funeral home in a state without authorizing legislation cannot legally perform the process regardless of whether it owns the equipment, so confirming availability locally is the first practical step.

A basic adult alkaline hydrolysis service typically costs between $1,295 and $4,600, with most providers around $2,500. That price generally covers transportation, the hydrolysis cycle, processing of the bone remains, a basic container, and death certificates. Families in states without a nearby facility may face additional transport fees of $200 to $500 to move the remains to the closest provider. Overall, the cost runs about $500 to $900 more than a comparable direct flame cremation, largely because providers are fewer and the equipment investment is substantially higher. A commercial system itself typically costs between $175,000 and $260,000, depending on capacity and automation.¹

1
Cremation Association of North America. Alkaline Hydrolysis
2
ASME. ASME Boiler and Pressure Vessel Code
3
Bio Response Solutions. Alkaline Hydrolysis
4
National Library of Medicine. Alkaline Hydrolysis of Mouse-Adapted Scrapie for Inactivation and Disposal of Prion-Positive Material