Funerary composting: use of Participatory Action Research to support a social transition – F-COMPOST

Our project was carried out with the ongoing involvement of researchers and members of the Humo Sapiens association, with a clear objective: the co-design and real-world testing of composting funeral procedures (i.e., experimentation). To achieve this, we received ongoing support from the U-Lille Science Shop, a specialist in participatory action research, which designed and led workshops and facilitated discussions. We also worked throughout the project with a graphic facilitator, who synthesized and illustrated our discussions and the project’s major milestones and deliverables.

Unlike traditional experimental research, in which the protocol is designed by researchers prior to the project, the F-COMPOST research program was structured in two phases: A/ co-design of the experimental protocols with stakeholders and B/ conducting the tests and generating useful knowledge—that is, knowledge that can be leveraged to inform public debate and decision-making (see Results section).

A/ Co-design of experimental protocols

An initial series of workshops helped us identify the key stakeholders to involve. To do this, we first identified the challenges of terramation by categorizing them (ethical, societal, economic, scientific, etc.). We then listed the stakeholders affected by each issue (researchers, practitioners, economic actors, policymakers, etc.). Finally, we used this information to identify the stakeholders necessary for the design and implementation of our experiments. We then reached out to and brought together these participants (July 2024) to collaboratively develop the terramation protocol to be tested.

The fifteen or so stakeholders identified in this way included experimental researchers (forensic taphonomy, archaeological anthropology, soil ecology, ecotoxicology), a sociologist, representatives of the Humo Sapiens association, a master composter, a cemetery manager, and a professional from a funeral cooperative.

The Humo Sapiens association presented the extensive conceptual framework developed prior to the project. Indeed, conducting experimental studies on technically unfeasible processes would make no more sense than devising a ritual that is technically impossible to perform. The association therefore explored a semi-burial approach, one that more closely resembles traditional burial and is thus better suited to meeting the wishes of the French people. Based on this, we chose to test green burial, an approach to body decomposition carried out below ground level. This vision, adapted to the French context, thus differs from humusation—a process carried out above ground—or from above-ground Natural Organic Reduction, already practiced in Germany and the United States.

From an operational standpoint, four complementary tasks were carried out:

1/ Collaborative analysis of trends in funeral practices and the current regulatory framework. Identification of stakeholders and scientific/technical challenges related to the development of terramation in France. Co-design of an experimental protocol (test conditions and monitoring parameters)

2/ Establishment of a logistical framework to enable the experiments by setting up and equipping two dedicated sites.

3/ Conducting on-site tests over a one-year period to collect data enabling a qualitative and quantitative assessment of the effectiveness of a terramation process (co-implementation)

4/ Production of deliverables in the form of scientific content (publications) as well as visual aids. Outreach and public communication on the subject. Development of a more reflective approach centered on undone science, funeral sciences, and the RAP methodology.

B/ Conducting tests and generating knowledge

In the fall of 2024, an initial series of small-scale tests (on rats) was conducted to verify the co-designed protocol, the selected materials, and to validate our working hypotheses.

As these tests were conclusive, we proceeded in June 2025 to bury 8 sheep.

It is important to note that carrying out these experiments has been challenging due to difficulties in securing a site and obtaining animal models. The site we developed and equipped at the University of Bordeaux has not yet been available for use (the application is currently under review by the prefecture). However, these challenges were identified prior to the project’s launch, and this issue was factored into our objectives. The fact that we were able to establish a comprehensive research infrastructure, including two operational experimental sites (the Bordeaux site is expected to become operational in the fall of 2026), should therefore be considered one of the project’s significant achievements.

Due to the time required to set up and conduct the tests (with follow-up at one year), we do not yet have all the results. The next steps and outlook are therefore as follows:

- Exhumation (week of July 6) of the animals buried in June 2025. Analysis of the results and publication of the findings;

- Publication of the results obtained in Australia (currently being drafted, scheduled for late 2026);

- Distribution of a summary document for the general public, featuring graphics combined with text to present the entire F-COMPOST project (fall 2026);

- Organization of a symposium/results presentation day (spring 2027).

Furthermore, the F-COMPOST project has already led to an extension in the form of a CNRS pre-maturation project aimed at developing a functional prototype for plant burial.

This research program results from a demand arising from civil society, which claim studies focusing on funerary composting. In this funeral process process, the body of the deceased is placed on a layer of plant shavings, then covered with the same material. Due to the natural degradation by aerobic bacteria and microfauna, the whole body rapidly changed into humus. This natural process thus reflects people's desire to limit their environmental footprint and give a meaning to their own death. However, its efficacy and innocuity need to be proved before claiming or an official recognition (i.e. legalization).

Due to its trans-disciplinary and inherent complexity, this question currently falls within the domain of undone science. Indeed, the involvement of a multitude of stakeholders from research, civil society, professionals and health agencies is required. Even limiting the issue to scientific questions, knowledge about funeral composting is scattered across an interdisciplinary spectrum ranging from funerary anthropology to ecology and from science to practical experience (the know-how of master composters). There is therefore no simple nor intuitive solution to answer such a question. Our approach is based on collective intelligence and focus on a main goal: testing funeral composting procedures under real field conditions (i.e. experimentation). For this purpose, we have built a transdisciplinary approach involving all the stakeholders combining experimental biology, mortuary anthropology and archaeology.

Our program is structured around four main tasks: 1/ a collaborative analysis of the evolution of mortuary practices and sanitary threat (anthropological perspective) to define the scientific/technical issues involved in funerary composting (co-design) 2/ the creation of experimental facilities 3/ the co-construction of funerary composting protocols, which will then be implemented to collect data and collectively validate their effectiveness (co-realization) 4/ the creation of scientific content (publications) as well as useful documents, i.e. short technical notes for decision-makers (legislative change) and association members. We also propose a more reflexive approach on undone science and Participatory Action Research. So, despite the risk-taking and breakthrough positioning, this project offers clear guarantees in terms of knowledge production, as well as the assurance of a strong societal impact.