Soil Research Pilot Study

Research has proven the Recompose process is safe and effective.

Research Details

In 2018, Recompose sponsored a research project with Washington State University’s Soil Science Department to prove that recomposition is a safe and effective means of disposition for humans. The following is the Executive Summary of that research.

Primary Researcher: Dr. Lynne Carpenter-Boggs

Research Institution: Washington State University (WSU)


Rapid biological conversion of human remains, including meeting a Process to Further Reduce Pathogens (PFRP) and all safety standards of compost.


New funerary options are sought for a variety of social, economic, and environmental reasons. Increasingly, cemetery plots are simply unavailable in urban areas. From March until August 2018, researchers at WSU completed the first scientific research trials of “recomposition,” which is the contained, accelerated biological conversion of human remains to soil-like material. Six human research subjects were recomposed during the five-month study.

WSU soil scientist Dr. Lynne Carpenter-Boggs and her team researched inputs, process, and product of recomposition. Temperature was tracked, and material was analyzed after four weeks or more. Recomposition of human remains – which is based on decades of research on livestock mortality composting – met all safety thresholds of WAC 173-350-220

Composting Facilities and Department of Ecology 05-07-034 for composting livestock mortalities.

This research provides a proof of concept that recomposition is an effective option for human death care. The research meets a critical need on a national level, and illustrates the revolutionary science for which WSU’s College of Agriculture, Human, and Natural Resource Sciences (CAHNRS) is known.


Recomposition is a managed thermophilic biological process used to convert organic material, including human remains, into a more stable earthy organic material that is unrecognizable as human remains. During the recomposition process, change occurs on a molecular level.

Recomposition uses the same process as closed vessel livestock mortality composting. The well-managed process of composting has gained favor for effective and sustainable management of livestock mortalities. Natural heating takes place when the right conditions are created for a thermophilic microbial community to thrive and decompose feedstocks. This is done by managing the choice of feedstocks, aeration, turning, and moisture.

During this process pathogens, soluble metals, and pharmaceuticals are reduced. The heat produced by microbial activity kills pathogens. Meeting a minimum temperature of 131 F or 55 C for 3 consecutive days provides a PFRP as defined by EPA 40CFR Part 503 App B. Furthermore, low populations of fecal coliform bacteria and E. coli must be confirmed in the post-PFRP product. Metal elements become bound in organo-metallic compounds as humic acids form. Most pharmaceuticals are reduced as they are also decomposed by microorganisms.


Dr. Carpenter-Boggs, Professor of Soil Science and Sustainable Agriculture at WSU-Pullman, holds an M.S. and Ph.D. in Soil Science. She has published several research and extension articles on compost science and has taught livestock mortality composting in public and academic arenas. She led a preliminary trial of a similar process at Western Carolina University with the Forensic Anthropology program. Mr. Rick Finch, manager of the WSU Composting Facility and Waste Management, assisted in the research. He has over a decade of experience in composting, including large animal composting of multiple species. Three graduate students and a post-doctoral assistant also assisted in the trial.


The Recomposition Science project sought and gained approval from the WSU Office of Research including ethical, legal, and biosafety assurances. Research subjects were donated per RCW 68.50.160(1). Subjects were handled per WA State Board of Health WAC 246-500-020, Contact with Human Remains. Trials were conducted at the WSU-Pullman Composting Facility which is permitted by Whitman County Health Department. The facility’s Department of Ecology air handling permit was modified and approved for the study.


The trial used a closed vessel rotating composting drum on the campus of WSU-Pullman. Two sections were managed simultaneously with three repetitions, for a total of six trials with six human research subjects. Plant-based feedstocks were placed in the vessel below and above each research subject. Moisture, aeration, and rotation were managed to provide optimal conditions for thermophilic microbial activity and decomposition of research subjects. Temperatures were recorded at 5-minute intervals. Observations and samples were taken after a minimum of 4 weeks. The resulting material was analyzed for elemental composition of carbon, nitrogen, phosphorus, and potassium. Heavy metal concentrations were analyzed including arsenic, cadmium, copper, zinc, lead, and mercury. The stability of the material was assessed by carbon dioxide and ammonium release, as well as populations of fecal coliform bacteria and E. coli.


Materials met standards for heating, microbial community, metal content, subject decomposition, stability, and product appearance after 4-7 weeks of recomposition. For each of the six trials, PFRP was met at least twice. All results for chemical and biological analyses were in the acceptable range per EPA 40CFR Part 503 App B & WAC 173 350 220.  Tests results for arsenic, cadmium, copper, zinc, lead, and mercury were all well under EPA limits. The initial water soluble content of the pharmaceutical drug Diazepam was reduced 95% by the recomposition process.


The process of recomposition has been shown to effectively and quickly biologically convert human remains. Final material was obtained that was unrecognizable visually, chemically, or microbiologically as human remains. This process provides an effective option for funerary care of human remains.

Subscribe to Our Newsletter

Join our growing community working to bring human composting to the world.

About Recompose

Recompose is a licensed, full-service, green funeral home in Seattle offering human composting. As the first human composting company in the world, we are a trusted leader in ecological death care. We are Seattle’s only human composting provider and serve clients across the U.S.

Recompose Seattle
4 S. Idaho St, Seattle, WA 98134
Open by appointment


Voted Best Funeral Home in Seattle Times’ Best in the PNW Contest 2023



Land Acknowledgement
Recompose acknowledges we make our lives and livelihoods on the lands of the Coast Salish People, specifically the Duwamish People. We honor with gratitude the Duwamish People past and present, the land itself, and the Duwamish Tribe. Colonization is an active, persistent process. Indigenous communities continue to be resilient in protecting their ecological and cultural lifeways and deathways despite ongoing oppression. Recompose respects, shares, and supports this commitment to climate healing and environmental justice. Join Recompose in contributing to Real Rent Duwamish.