In a push for eco-friendly burial alternatives, Washington became the first state to allow "human composting" when Gov. Jay Inslee signed legislation Tuesday that approved the process that turned bodies into soil within weeks.

Human composting, or "natural organic reduction," relies on a mixture of materials, such as wood chips and straw, to produce about two wheelbarrows' worth of soil. The legislation signed into law Tuesday will allow licensed facilities to offer the service.

The law also allows loved ones to keep the soil in urns, similar to cremation, spread it in public lands or use it to grow plants on private property.

Proponents of the law say it will help reduce the demands on space needed after a person dies, curb pollution from chemicals pumped into buried bodies that can seep into groundwater and reduce carbon emissions from cremation. It also can help with the planting of trees.

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"It is sort of astonishing that you have this completely universal human experience – we’re all going to die – and here’s an area where technology has done nothing for us. We have the two means of disposing of human bodies that we’ve had for thousands of years, burying and burning," the bill's sponsor, Democratic Sen. Jamie Pedersen of Seattle, told USA TODAY in April. "It just seems like an area that is ripe for having technology help give us some better options than we have used."

The legislation was inspired by Katrina Spade, a graduate student who came up with the idea by modeling it from a method farmers use to dispose of livestock.

Spade found that a mixture of wood chips, alfalfa and straw can convert bodies to soil within four to seven weeks. She tested it during a pilot program at Washington State University with six human bodies.

Spade then later founded Recompose, a company that provides body decomposition services to the public.

The law takes effect May 1, 2020, the Seattle Times reported. Previous laws allowed for only cremation or traditional burials to dispose of remains in Washington.

Other green burial methods, like using a biodegradable casket, are growing in popularity around the country in recent years. The law also allows for alkaline hydrolysis, or "liquid cremation," the Times reported.

After actor Luke Perry died in March, he was buried in an eco-friendly mushroom suit that is biodegradable.

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"To be able to provide more options for people’s choices is a very exciting thing," Rob Goff, executive director of the Washington State Funeral Directors Association, told USA TODAY last month.

Pedersen, though, said he's received angry emails form constituents who oppose the legislation.

"The image they have is that you’re going to toss Uncle Henry out in the backyard and cover him with food scraps," Pedersen said. But the process is respectful, the state lawmaker said.

Spade said in April, "Our goal is to provide something that is as aligned with the natural cycle as possible, but still realistic in being able to serve a good number of families and not take up as much land as burial will."

Contributing: The Associated Press

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