How Alkaline Hydrolysis Works

Since time immemorial, human beings have buried their dead in the ground. Archeological evidence also indicates that people have cremated their loved ones since at least 11,500 years ago—and probably well before that.

Alkaline hydrolysis, a relatively new form of body disposition, offers some distinct "green" advantages over both of these methods in today's eco-conscious environment and could potentially become a significant body-disposition option in the future—provided it overcomes two obstacles: public squeamishness and a multitude of regulatory hurdles.

Tombstones in a grassy field
Edgar Bibian / EyeEm / Getty Images

The Process

Alkaline hydrolysis uses water, potassium hydroxide (a common ingredient in liquid soap), relatively low heat (177 C, 350 F) versus cremation, and pressure to reduce the body of a deceased loved one to bone fragments and an inert liquid. The process only works on protein-based materials, so the body must be dressed in certain types of natural-fiber clothing, such as silk, leather or wool.

The body is next placed within a stainless-steel alkaline hydrolysis chamber. The entire process takes roughly 2 to 3 hours, which is equivalent to the time necessary for an average cremation.

Once alkaline hydrolysis is complete, the remaining bone fragments are rinsed and then pulverized to dust or "ash" (this also occurs with the bone fragments that remain after cremating a body). This dust can be returned to the surviving loved ones in an urn for placement in a cremation niche, scattering in a special place, burial, or any other option those choosing to cremate a loved one might select.

As noted earlier, the second byproduct of the alkaline hydrolysis process is an inert liquid, which does not contain human DNA or other genetic material. After filtering and purification at a water-treatment facility, this fluid can be introduced into Earth's natural water cycle.

The alkaline hydrolysis process is also called Resomation and BioCremation (both trademarked terms), as well as the general terms "flameless cremation," "chemical cremation," "green cremation," and "aquamation."

The Benefits

Compared to burial or cremation—the two typical forms of body disposition—alkaline hydrolysis offers several advantages in terms of ecological impact. The process uses less energy compared to cremation, which relies on natural or propane gas to reduce a human body to bones through combustion.

While significantly lower than the emissions resulting from various manufacturing and energy-creation processes, cremating a body also results in carbon dioxide (CO2) emissions that can contribute to greenhouse gases.

Moreover, many people have fillings in their teeth that contain mercury, which was once commonly found in the amalgam dentists used to fill cavities. The high temperatures of an average cremation (760 to 982C, 1400 to 1800F) can vaporize those fillings, releasing harmful emissions into the atmosphere. In contrast, the lower temperature of the alkaline hydrolysis process results in fewer harmful emissions because it's insufficient to heat this dental amalgam to the point that it releases mercury vapor. Instead, dental fillings remain in solid form throughout the process and are separated from the bone fragments before the latter are rinsed and pulverized.

Finally, unlike traditional ground burial, the remains of the alkaline hydrolysis process reduce the demand on land-space. Even if surviving loved ones choose to bury the remains in the ground, the amount of burial space necessary is significantly less than that of a traditional casketed burial.

The Obstacles

A 2008 ABC News article on alkaline hydrolysis describes the fluid remaining after the process is finished as a "coffee-colored liquid [with] the consistency of motor oil and a strong ammonia smell." Descriptions such as this one play upon the fact that human beings generally do not like to imagine a human body in any form other than the one they know in life. Even cremation, which now accounts for the bodily disposition of someone in four U.S. citizens, faced decades of bias and rejection by funeral service practitioners and the public alike because it involved flames. Thus, the idea of reducing a human body to "coffee-colored motor oil" understandably presents a significant hurdle that alkaline hydrolysis must now overcome despite any apparent benefits.

In addition, another tremendous obstacle alkaline hydrolysis must overcome is the regulatory morass governing the facilities that process dead bodies in the United States and worldwide. Any funeral home or crematory interested in adding alkaline hydrolysis to its services faces a multitude of regulatory hurdles. In the U.S., 20 states allow alkaline hydrolysis as of February 2020.

3 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. The Washington Post. Scientists: Oldest human found in Alaska is a child, cremated 11,500 years ago.

  2. ABC News. New in mortuary science: Dissolving bodies with lye.

  3. Cremation Association of North America. Alkaline Hydrolysis.

By Chris Raymond
Chris Raymond is an expert on funerals, grief, and end-of-life issues, as well as the former editor of the world’s most widely read magazine for funeral directors.