stacked stones on ocean shore, sunset

Death is just one point on the circle of life and dying sustainably takes just as much mindful planning as living sustainably does. Most people avoid thinking about death, but modern death care practices make funerals a tradition with some rather deadly environmental impacts. Fortunately, more sustainable options like aquamation are become easier to access, so environmentalists can rest a little easier now about how sustainably they are going to rest in peace later.

Conventional Death Care

In most places, regulations for death care don’t leave a lot of room for the environment. Humans are no longer allowed to decompose six feet underground in a natural pine box. Modern burial requires the use of toxic, persistent chemicals for embalming. Caskets use the wood from four million square acres of forest each year. More than 1.5 million tons of concrete are used to construct burial vaults while 104,000 tons of steel and 2,700 tons of copper and bronze are used in burial materials. All told, burials result in 178 tons of carbon dioxide emissions yearly. About 827,000 gallons of formaldehyde-based embalming fluid leak into the soil and groundwater annually.

Cremation is better for the environment. Bodies are typically stored in cardboard rather than wooden caskets before burning. In the U.S., crematoriums are required to use filtering systems that remove pollutants (like mercury from dental fillings). But burning still uses a lot of energy (crematoria are usually powered by nonrenewable natural gas) and produces greenhouse gas emissions. Each cremation still produces as much CO2 as a flight from London to Rome, for a total of about 360,000 metric tons of CO2 emissions each year.

There are some eco-friendly options for natural burials. And there are several environmentally friendly uses for cremains, like tree cremains urns and coral reef restoration. A few states have even begun to allow human composting.


Initially developed in an agricultural context in the late 20th century, aquamation was then used by research institutions for human remains that had been donated to science. Aquamation has been commercially available in several states since 2011. But it has only recently received public attention after the body of Archbishop Desmond Tutu was aquamated early in 2022. Aquamation, like composting or cremation, is a method of rapid decomposition. Both methods use heat – composting uses the heat naturally generated by decomposition, while cremation uses powerful furnaces. But aquamation, as the name suggests, takes place in a liquid solution.

Sometimes described as “water cremation,” aquamation is a chemical process called alkaline hydrolysis, which dissolves the body. Although chemical dissolution sounds more horrifying than ecological, it isn’t particularly gruesome. The body is placed in a container with a liquid solution made of potassium hydroxide (aka lye) and water and heated to 300 F – a fraction of the 1,200 F required for cremation. The solution is strongly basic (as opposed to acidic). But it has the same result, which is a chemical reaction between the body and the solution.

What Remains of the Remains

The chemical reaction leaves behind only bone fragments and liquid. The resulting liquid is a sterile combination of salts, sugars, amino acids, and peptides in water, with no residual tissues or DNA. This liquid can be safely discharged with wastewater.

The remaining bone fragments can be heat dried or allowed to dry naturally to save energy. Then they are pulverized using the same method that follows heat cremation. Families can claim these “ashes” just as they can for cremains. Aquamation “ashes” will require a larger container than ashes from cremation but will have a finer, brighter white appearance. All told, aquamation is estimated to have one-fourth the carbon footprint of cremation. Aquamation is often considered a gentler process because medical devices like pacemakers (which can explode inside a furnace) do not have to be removed from the body before aquamation.

Aquamation Options

The aquamation of pet remains is legal everywhere in the U.S., and most states have pet aquamation providers. For human remains, it is currently legal in most states, although roughly half as many have active providers. Some providers are able to receive bodies shipped from other states. Where aquamation has been legalized, it is usually defined as a form of cremation and most providers are crematoria. The Cremation Association of North America maintains a map of regulatory changes in U.S. and Canadian states as aquamation becomes more common. Where aquamation is available, costs average around $3,500. That places it between the lower costs of cremation and the higher costs of burial.

What Are Your Local Green Burial Options?

Sustainable burial methods such as aquamation, body composting, and natural burial are growing in popularity, but access to these options varies widely from state to state. Find out which sustainable burial services are available in your state, and learn which states have the greatest number of sustainable options in The Greenest States To Die In, a report by insurance provider Choice Mutual.

Memorial Glass Using Aquamation Remains: An Explosive Result

As cremation gained popularity, the use of cremated ashes in memorial glass, which use a loved one’s ashes as part of a glass design has become a frequent and lovely choice for remembering losses.

Bob Meyer, of Ocean Beaches Glassblowing in Seal Rock, Oregon, alerted us to the potential dangerous results of using aquamation remains in memorial glass:  “Every single aquamation sample I’ve dealt with — about a dozen now — is a light yellow, not white. And every time I’ve even touched hot glass to these ashes, they burst into up to foot-tall flames and release extremely foul-smelling smoke.”

Aquamation remains, unlike cremation remains, contain more organic material that has not been oxidized during the process. Those organic elements can burst into flames when they come into contact with high heat. We checked this result with several glassblowers who make memorial glass, and four out of five responded that they’ve seen explosive flames and acrid smoke when working with aquamation remains.

The common element in each story that led to flames was that the remains appear more yellow than white, which remains are typically expected to be. This may reflect that the ashes are not completely processed during aquamation.

“The more yellow they are it seems to me the more likely they are to be volatile,” said Michelle Kaptur of Soulbursts. “I don’t see that many of them but they have gotten better from say a year ago.”

If you choose aquamation, consult with the provider to ensure that the remains are not volatile before sending them to a glassblower for use in memorial glass.

Editor’s note: This article was updated with additional information about the risks of using aquamation remains in memorial glass in August 2023.

By Gemma Alexander

Gemma Alexander has an M.S. in urban horticulture and a backyard filled with native plants. After working in a genetics laboratory and at a landfill, she now writes about the environment, the arts and family. See more of her writing here.