The Real Impact of Alkaline Hydrolysis (Disposition Eco-Impact, Part 3 of 5)

Cremation Funeral Industry News October 3, 2023
Alkaline Hydrolysis Machine
Aries Jo

Aries (they/them) is a certified Celebrant and the Director of Outreach and Education at Parting Stone where they create forward-thinking content for funeral professionals. Aries leads the Death Curious online community and hosts the Death Curious podcast. Learn more about Parting Stone and their complete alternative to cremated remains here.

The Real Impact of Alkaline Hydrolysis (Disposition Eco-Impact, Part 3 of 5)

This article was originally published on the Death Curious blogAlexandra Jo and Parting Stone launched Death Curious with the mission of eliminating death avoidance and bringing people together with death-positive education. This is the third in a series of five deeply-researched articles exploring the real eco-impact of the various forms of disposition.

Alkaline hydrolysis, also known as water cremation, is an eco-friendly disposition method with extremely little impact on the environment. The process involves respectfully placing an individual body in a stainless steel vessel, in which a gentle flow of alkaline water and precisely controlled temperature accelerate the natural hydrolysis process for the soft tissue. All of the soft organic material of the body is dissolved to its most basic components (sugars, fats, salts, etc.) during the process, which leaves behind no DNA or RNA just as with flame cremation. The loved ones of the deceased get back the ground bones in “ash” form after the process, again, just as with flame cremation. 

There is a plethora of scientific, peer reviewed data and research available which shows that the alkaline hydrolysis process is one of the most eco-friendly disposition methods available in today’s death care landscape. Thus, when we consider the consumer research presented in the first two installments of this series which states that nearly 60% of today’s consumers will change their buying habits to be more green, it’s clear that alkaline hydrolysis has the potential to become one of the most desired disposition methods in the coming years. 

Resistance Within the Profession 

According to research by Aquamation, alkaline hydrolysis offers “over 90% energy savings when compared to flame-based cremation.” For an innovative, respectful, heavily researched disposition option with few downsides, it’s surprising that alkaline hydrolysis has received a large amount of resistance within the death care profession. The process is only legal in 26 states, despite being enthusiastically well received by the public and younger generations of death planners.

For some, this process may raise questions about whether the liquid flushed back into the municipal water treatment cycle is safe and respectful. However, with a better understanding of the process (especially when compared to embalming) it becomes quite clear that alkaline hydrolysis is safe for the environment, and dignified for people.

Aquamation explains that, “The water-based process uses a solution of 95% water and 5% alkali (a combination of sodium and potassium hydroxide). The alkalis used in this process are the same alkalis used in common cosmetic products, body washes, shaving creams, and even in food preparation. At the end of the process, the chemical has been completely consumed, neutralized, and no longer remains in the water solution. The water is returned to the ecosystem via the normal wastewater treatment facility, just as all funeral homes in the United States do during the embalming process. The Aquamation process produces a completely sterile solution of amino acids, sugars, nutrients, salts, and soap in a water solution. These are the byproducts of natural decomposition.

Research and Data

The “90% energy savings” cited by Aquamation is based on research performed by a team of scientists in the Netherlands conducting a study comparing the environmental impact of four disposition methods (traditional burial, cremation, alkaline hydrolysis, and cryomation). The study researched 10 areas of impact including acidification, global warming contribution, ozone depletion, freshwater ecotoxicity, terrestrial ecotoxicity, among others. 

Research found that, of those four disposition  methods, alkaline hydrolysis has the lowest overall impact on the environment (AH was lowest in every category except for eutrophication, or putting high amounts of nutrients into the environment in a way that could upset a delicate ecosystem), using fewer resources and less energy than the other methods, and having much of the energy usage offset by metals recycling. The study concludes that “Cryomation and resomation have the lowest environmental impact in all categories, except for eutrophication.” 

To learn more about how alkaline hydrolysis compares to other disposition methods when it comes to environmental impact, download the free ebook “The Real Eco-Impact of Disposition Methods” by Death Curious: 

Alkaline Hydrolysis and Metals Recycling Offsets

Even though green burial technically uses the least amount of energy as far as electricity goes, and NOR uses the least fossil fuels, the reclamation of metals from bodies that undergo alkaline hydrolysis more than offsets this energy gap.

While alkaline hydrolysis is already inherently low in energy use, pollution, and global warming contribution, metals recycling means that a big portion of the small emissions and energy usage that is produced with alkaline hydrolysis can also be offset, lowering the method’s overall environmental impact significantly. In fact, according to the Netherlands study, metals recycling can even make alkaline hydrolysis have a net positive eco-impact in some areas.

Information gathered from Aquamation’s environmental impact research states that, “The ability to recycle metals provides an enormous environmental benefit. In fact, a 2011 study on the impact of funeral practices (Keijzer 1, 2) found that alkaline hydrolysis is more environmentally friendly than even natural burial.  Even though green burial directly uses the least amount of energy, the reclamation of metals from bodies that undergo alkaline hydrolysis more than offsets this energy gap.” 

There are other heavy metals that need to be recycled from human remains, and research from Aquamation elaborates, “We can look to the types of metals used for implants and how they are made to understand the environmental credit of the recycling.  Most medical implants are made of titanium.  While titanium is the ninth most abundant element on Earth, its acquisition comes with a steep environmental cost. The cost to obtain and transport the materials used to make titanium – often from other countries – is one aspect, while the actual process to turn it into usable products is another (extraction, purification, reactor, alloy creation, and byproduct management).  According to the United States Geological Survey, the US has become highly dependent on the import of materials used to make titanium. A 2017 Italian study (De Angelis, et al.) found that the average person contains one half pound of metal from implants. Metal implants are even more common in the United States and Canada” 

The metals recycling that is possible when families choose alkaline hydrolysis offers a huge benefit to the environment by recirculating metals that we already have access to back into the market, which lowers the need for more mining and new metals acquisition. 

Alkaline Hydrolysis: A Nearly Net-Zero Impact 

The article “Dissolving the Dead: A Radical Alternative to Cremationand Burial” from BBC breaks down the findings of Dutch researcher, Elizabeth Keijzer, from a study comparing the eco impact of disposition methods in the UK. The study found that alkaline hydrolysis was the least environmentally impactful disposition method available to date. The BBC article explains, 

“According to Dutch researcher Elisabeth Keijzer, who has carried out two studies for the Netherlands Organisation for Applied Research (work commissioned by a funeral chain, Yarden), [alkaline hydrolysis] is much better. Her two reports published in 2011 and 2014 make for fascinating if macabre reading. She breaks down burial, cremation and alkaline hydrolysis into dozens of steps, which she assesses against 18 environmental impact yardsticks – such as ozone depletion, marine eco-toxicity and climate change. In 17 of these categories alkaline hydrolysis comes out best. Cremation is worst in the most categories (10), but burial is deemed to have the highest overall environmental impact. Alkaline hydrolysis is found to result in the emission of seven times less CO2 than cremation. To summarize the results, Keijzer and her fellow researchers calculated a “shadow price” for each method – the lowest amount of money it would theoretically cost to either compensate for the environmental impact, or avert it. For burial, the net cost was 63.66 euros per body. For cremation, it was 48.47 euros. For alkaline hydrolysis, just 2.59 euros.”

Overall, alkaline hydrolysis is a safe, respectful method of disposition that has virtually no impact on the environment. The water returned to wastewater treatment facilities is a completely sterile solution of amino acids, sugars, nutrients, salts, and soap in a water solution. This is comparable to all of the fluids and body materials flushed into water systems by all funeral homes in the United States during the embalming process. Alkaline hydrolysis machines like the ones available from Resomation, and the cremulators used to pulverize bones after the alkaline hydrolysis process use very little electricity. Furthermore, metals recycling often more than offsets the minimal environmental impact that alkaline hydrolysis has. 

The Future of Alkaline Hydrolysis 

As more people in the US are seeking out eco-friendly disposition methods and funeral practices, it stands to reason that aquamation will continue to grow in popularity. Another article from Choice Mutual outlines how funeral practices have changed in the US just since the onset of the Covid-19 pandemic, and reveals that younger generations are more educated about and aware of alkaline hydrolysis. This data suggests that alkaline hydrolysis will only continue to grow in popularity in the coming years. For funeral businesses, this means that figuring out how to incorporate alkaline hydrolysis into business strategies for the future will most likely be a lucrative investment of time, energy, and money. 

To learn more specifics about how alkaline hydrolysis stacks up to the other disposition methods when it comes to eco-impact, where alkaline hydrolysis is currently available in the US, and how to offer it to your families in the future, click below to download the full ebook guide “The Real Eco-Impact of Disposition Methods”