"Recomposition offers an alternative to embalming and burial or cremation that is natural, safe, sustainable, and will result in significant savings in carbon emissions and land usage," Katrina Spade, who worked to develop the process and lobbied for the bill, told AFP.

Spade developed the idea through a nonprofit called the Urban Death Project and has now started a small business, Recompose. She hopes to open the country's first "organic reduction" funeral home, The Seattle Times reported.

"I feel so happy," Spade told The Seattle Times. "I can't believe we've come all this way, but here we are."

Spade and her colleagues place a body in a steel container filled with alfalfa, wood chips and straw and let it sit for around 30 days, BBC News explained. At the end of that period, the body decomposes into two wheelbarrows of soil that can be used to plant flowers or trees.

Washington State University soil scientist Lynne Carpenter-Boggs helped run a test of the process in 2018 with the remains of six terminally ill volunteers who supported the project. She found that the soil met all federal and state safety standards for pollutants like metals, The Seattle Times reported.

People's Memorial Association Executive Director Nora Menkin, who attended the signing with around 20 supporters of the bill, said that Inslee seemed excited about the new law.

"Inslee congratulated Katrina pretty effusively," Menkin told The Seattle Times.

Traditional burials have a number of ecological drawbacks, as The Smithsonian explained:

Each after-death action comes with its own set of environmental impacts, from embalming chemicals that leach into groundwater to transportation emissions. Many cremation facilities lack modern filtration systems and spew carbon dioxide and mercury into the atmosphere. Cemeteries themselves carry an environmental cost: Many depend on fertilizers and large amounts of water to maintain that clipped, mowed look.

Washington already has "green" cemeteries where people can be buried without embalming, coffins or headstones. Spade's process is more like a green alternative to cremation, The Seattle Times said.

"I think this is great," Funeral Consumers Alliance Director Joshua Slocum told The Seattle Times. "In this country, we have a massively dysfunctional relationship with death, which does not make good principles for public policy. Disposition of the dead, despite our huge emotional associations with it, is not — except in very rare cases — a matter of public health and public safety. It's a real tough thing for people to get their minds around, and a lot of our state laws stand in the way of people returning to simple, natural, uncomplicated, inexpensive ways of doing things."

Menkin said she knew of people in Massachusetts and Michigan who now wanted to bring similar bills to their states.