MarILCA Characterization Factors for Microplastics, Tire Particles and Cellulosic Fibers in Life Cycle Assessment: Regionalized impacts in marine, freshwater and terrestrial ecosystems

(all versions; resolves to the latest version)

This repository provides the code and data used to compute fate factores (FFs) and characterization factors (CFs) based on SimpleBox object-oriented (SBoo). SBoo Version 2026.4.0 is used (https://github.com/rivm-syso/SBoo/releases/tag/2026.4.0). Earlier releases of this repository used SBoo 2026.3.1 (https://doi.org/10.5281/zenodo.19388881)

This repository provides all scripts and input data required to:

• Compute steady-state and dynamic CFs
• Retrieve default CFs
• Generate graphs and figure

If you use the CFs, please cite:

• The publication: Saadi, N., Hajjar, C., Ospital, L., Quik, J.T.K., Corella-Puertas, E., Hids, A.R., Lebrun, M., Louvet, J., Tang, Y., Thonemann, N., Boulay, A.-M. (2027). MarILCA characterization factors for microplastics, tire particles and cellulosic fibers in life cycle assessment: the PEBBLE method for regionalized physical impacts in marine, freshwater and terrestrial ecosystems. Resources, Conservation and Recycling, 237, 109193. https://doi.org/10.1016/j.resconrec.2026.109193
• The version used, with its DOI (see Versions below)

Citation metadata is also provided in CITATION.cff ("Cite this repository" on GitHub).

Versions

Version	Date	DOI	SBoo version	Main changes
v1.1.0	2026-10-28	10.5281/zenodo.23735051	2026.4.0	TRWP-specific EEFs in water and soil, Linen soil degradation update, ReCiPe midpoint and endpoint CFs, faster code
v1.0.0	2026-05-08	10.5281/zenodo.20087937	2026.3.1	First public release

All versions: 10.5281/zenodo.20087936. The list of changes is in CHANGELOG.md.

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1. Install SBoo

To install SBoo, open R and run:

source("InstallSBoo.R")

This will:

• Install the selected version/branch of SBoo.
• Create a new folder called SimpleBox, which will contain SBoo and SBooScripts folders.

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2. Run

Steady-State CFs

source("02_Run_SB_CI.R")

Run settings are at the top of the script (section "Run settings"):

• n_samples: number of Monte Carlo runs per combination (default 100)
• n_cores: by default, all cores but one on macOS/Linux, where the polymers of each region are run in parallel (forked processes) with a fixed seed per polymer (parallel_seed), so results are reproducible. On Windows, forking is not available and the script runs serially (n_cores = 1). The serial run reproduces the random number stream of previous versions, so its Monte Carlo samples differ from the parallel run
• Loop subsets and results_suffix can be set for quick tests without overwriting the results

Tire and road wear particles (TRWP) use TRWP-specific effect factors (physical effects) in water and soil: EEF_water = 18.521 [1.688 - 203.244] and EEF_soil = 0.197 [0.038 - 2.141] PAF m3/kg (95% CI). The sediment EEF is the same as for the other polymers.

Dynamic Simulation

source("04_Run_SB_Dyn.R")

All outputs are saved in:

/results/

Where the following are stored:

Steady sate FFs and CFs:

 /results/SI_C.xlsx 

Time-horizon dependent FFs and CFs:

 /results/SI_D.xlsx

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3. Default CFs

To compute the default characterization factors (CFs):

source("03_Default_CF.R")

These CFs are based on:

• Emission weighted averages of CFs for unknown material CFs
• Regional emission weighted CFs of plastics for unknown emission location
• Default size (diamter or thickness) CFs for each shape/material
• A decision tree is provided in Figure S.19 to select the appropriate CF

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4. ReCiPe CFs

To compute the ReCiPe CFs for the three cultural perspectives (Individualist: 20 years, Hierarchist: 100 years, Egalitarian: steady state), run from the repository root after 03_Default_CF.R:

source("results/ReCiPe/ReCiPe_CF.R")

This creates results/ReCiPe/ReCiPe_CF.xlsx with:

• Midpoint CFs in kg PET, 1µm, sphere, rw-eq/kg (freshwater), sw-eq/kg (marine) and ns-eq/kg (terrestrial physical effects), one sheet per cultural perspective. Reference flow: PET, 1µm, sphere, World region, emitted to river water (rw), seawater surface (sw) or natural soil (ns)
• Endpoint CFs (species·yr/kg), one sheet per cultural perspective
• Midpoint to endpoint conversion factors (species·yr/kg PET, 1µm, sphere, rw/sw/ns-eq)

Midpoint and endpoint sheets have one row per flow and impact category. The variables are documented in the README sheet of the file.

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5. Repository Structure

├── data/                         # Scenario-specific datasets for SBoo
├── input/                        # Model input files (Regionalized data and TrackMPD data)
├── results/                      # Model outputs
│   └── ReCiPe/                   # ReCiPe midpoint and endpoint CFs (ReCiPe_CF.R, ReCiPe_CF.xlsx)
├── figures/                      # Figures shown in the publication and the code to make them
│   ├── SI_Graphing.ipynb         # Graphing and visualization notebook (figures of the publication and SI)
│   └── Plot_comparison_with_main.R  # Figure of the CF changes per material vs the previous version
├── previous marilca cfs/         # Previous CF datasets (MarILCA)
│
├── InstallSBoo.R                 # Installation script
├── installRequirements.R         # Installation
├── 02_Run_SB_CI.R                # Main steady-state model run
├── 03_Default_CF.R               # Default CF calculation
├── 04_Run_SB_Dyn.R               # Dynamic model run 
├── Compare_with_main.R           # Comparison of SI_C/SI_D with another git branch (default: main)
│
├── CHANGELOG.md                  # List of changes per version
├── CITATION.cff                  # Citation metadata (also used by Zenodo)
├── LICENSE.md
└── README.md

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License

Creative Commons Attribution Share Alike 4.0 International, as specified in LICENSE.md.