California becomes the 15th state to approve the process, which advocates say is better for the environment than fire-based cremation.

“A final spa treatment” is how one person described it to Barbara Kemmis.

But instead of melting away stress and worries, this treatment dissolves human remains.

This so-called “water cremation process” is gaining in popularity.

It offers people the option of having their remains dissolved in a hot chemical liquid bath.

Advocates say it’s a more environmentally friendly option than burial or fire cremation.

A proposal to legalize the process — also known as biocremation, flameless cremation, or more specifically, alkaline hydrolysis — in California was signed into law by Gov. Jerry Brown on Sunday evening.

That makes California the 15th state to legalize “water cremation,” according to Kemmis, executive director of the Cremation Association of North America.

The “spa treatment” involves placing the body on a tray in a large oven-like machine that’s then filled with heated water and potassium hydroxide, or lye.

The solution speeds up the natural decomposition of the body, leaving behind only bones and any pacemakers, implants, or tooth fillings after 2 to 12 hours.

The bones can be dried, pulverized into a powder, and scattered or stored like ashes.

“All biological material is gone,” Kemmis told Healthline.

She explained that about 30 percent more remains are left behind than in fire cremation, where some tinier finger or ear bones are often incinerated.

“It’s pretty much a skeleton — with no ligaments or muscles,” she said of water cremation.

Like a traditional fire cremation, no DNA is left behind either.

And, unlike a fire cremation, the carbon footprint is minimal.

Burning a dead body results in the release of the carbon dioxide stored in the body and in the fuel.

It also releases the mercury contained in tooth fillings, something water cremation doesn’t do.

Burying a body takes up resources for the casket and land, as well as introducing chemicals like formaldehyde.

Kemmis said the number one reason consumers cite for their interest in water cremation is environmental concerns, namely the lower carbon footprint.

Although, she said, the footprint isn’t necessarily zero because the water still needs to be heated up.

But increasing the energy efficiency of cremations could have significant impacts.

“Twenty-five years ago, the cremation level was around 15 to 20 percent,” said Terry McHale, a Sacramento lawyer and legislative advocate of the California Funeral Directors Association.

But last year, he noted, 62 percent of the 200,000 Californians who died were cremated.

“There’s been a total shift in the way we deal with death and the disposition of our loved ones,” McHale told Healthline. “Cremation clearly is the most popular option right now, and liquid cremation just provides a different option for those who want to do it.”

The California legislation was proposed by state Assemblyman Todd Gloria, D-San Diego, after his office was approached by a company in his district, Qico, that manufacturers alkaline hydrolysis equipment.

It’s the third time such legislation has been proposed in the state but the first time it’s made it to the governor’s desk.

Gloria’s spokesman, Nick Serrano, said legislators had balked at what to do with the wastewater in past legislation.

But an alkaline hydrolysis facility that the University of California Los Angeles (UCLA) uses to dispose of medical cadavers has proven there’s a safe and sanitary solution by sending the water into tanks and transporting it for treatment, Serrano said.

He added that the newlaw requiresthe water to be taken to a facility where it’s either turned into bioenergy or, if safe, disposed of in the sewage system after treatment.

“It’s about giving Californians another choice in how they dispose of remains,” Serrano told Healthline.

He said Gloria’s office hasn’t heard much from constituents on the bill, “but it’s necessary to think about this. All of us are going to die and we all need to make a choice about how we’re going to be treated after death, and this is about giving Californians a choice for something that’s more environmentally friendly than traditional cremation.”

California wouldn’t be the first.

“It’s not a unicorn. It does exist in nature in other states,” Serrano said.

But, according to Kemmis, only 5 out of the 15 states where the process is legal currently have operating facilities. They are Florida, Illinois, Minnesota, Maine, and Oregon.

She said her organization tracks cremation stats and only a fraction of a percent of cremations are currently water cremation — despite it typically costing the same or “a little higher” than traditional cremation.

“It could be a chicken-and-egg dilemma,” Kemmis said. “There won’t be demand for it until it’s widely available and it may not be widely available until there’s sufficient demand.”

“We’ve had maybe half a dozen inquires over the last year,” Kemmis said. “But sometimes we have to tell them they’ll have to go out of state.”