ED Sciences Chimiques
Environmental impacts of bio- and fossil-based packaging: modelling the fate of plastic leakages in life cycle assessment
by Bilal ERRADHOUANI (Institut des Sciences Moléculaires)
The defense will take place at 14h30 - Amphithéâtre PA-C0-02 ENSMAC (CNRS UMR 5629), Université de Bordeaux, 16 Av. Pey Berland
in front of the jury composed of
- Philippe LOUBET - Maître de conférences - Bordeaux INP - Directeur de these
- Arnaud HELIAS - Directeur de recherche - INRAE - Rapporteur
- Stéphane BRUZAUD - Professeur des universités - Université Bretagne Sud - Rapporteur
- Myriam SAADE - Chargée de recherche - CNRS - Examinateur
- Jérôme CACHOT - Professeur des universités - Université de Bordeaux - Examinateur
- Véronique COMA - Maîtresse de conférences - Université de Bordeaux - CoDirecteur de these
Since the mid-20th century, plastics have become a cornerstone of modern societies, spreading across all sectors and supporting the expansion of production systems and the globalization of trade. This widespread use has, however, led to increasing environmental pressures: nearly 9,500 Mt of plastics have been produced since the 1950s, with the sector accounting for approximately 4.5% of global greenhouse gas (GHG) emissions. In addition, around 8 million tonnes of plastics enter the oceans each year, where they persist, disperse, and expose marine organisms to a range of ecotoxicological risks. The packaging sector, which accounts for about 40% of global production, therefore represents a key leverage point for reducing plastic pollution. In this context, bio-based packaging is often promoted as an alternative to fossil-based plastics to reduce GHG emissions and dependence on fossil resources. Frequently conflated with biodegradable plastics under the umbrella term “bioplastics,” these materials have gained considerable attention, although their broader environmental implications remain uncertain. Life Cycle Assessment (LCA) provides a robust framework to inform such substitution. However, current approaches still struggle to systematically account for plastic leakage in ecosystem damage indicators, potentially leading to an underestimation of impacts. This thesis aims to develop a methodological and applied framework to assess whether bio-based packaging can reduce environmental pressures compared to conventional alternatives from a life cycle perspective. Based on a literature review, a harmonized LCA of bio-based and fossil-based packaging highlights trade-offs between climate change mitigation and ecosystem impacts. While bio-based materials can reduce GHG emissions through biogenic carbon storage, they may also increase pressures on ecosystems, particularly due to land use. Circular strategies combining feedstock selection and end-of-life management can help mitigate these trade-offs. A critical review of new LCA methods addressing plastic leakage reveals key limitations, notably the lack of explicit consideration of macroplastic fragmentation into secondary microplastics in the marine environment. A methodological framework is proposed to incorporate this process into dynamic fate models, leading to the development of new characterization factors. Experimental results further highlight the limitations of polymer-based approaches and demonstrate the relevance of a formulation-based perspective, which better captures the behavior of real packaging materials. Integrating these developments into the LCA framework enables a more comprehensive assessment of impacts. In regions with insufficient waste management infrastructure, plastic leakage significantly contributes to ecosystem damage, mainly through the formation of secondary microplastics from packaging fragmentation at end of life. Rapid degradation or sedimentation in marine environments can mitigate these impacts, regardless of whether the polymers are bio-based. At the European scale, the integrated assessment shows that substituting conventional packaging with bio-based alternatives can reduce GHG emissions, but may also lead to increased pressures on ecosystems. Overall, these findings indicate that material substitution alone is not sufficient. Transitioning toward more sustainable packaging systems also requires reducing demand, promoting reuse, and improving end-of-life management.