The environmental pollution caused by post-consumer plastics and the associated health risks necessitate comprehensive life-cycle analyses of these materials, mainly focusing on their end-of-life impacts. This study presents an in-depth evaluation of the environmental implications of producing nanocomposites using poly(3-hydroxyoctanoate) (P(3HO)), a biodegradable and biocompatible polymer that holds great promise as an alternative to traditional plastics, in combination with calcium-, and zinc-based double-layered hydroxides (LDH) modified with the antioxidant α-tocopherol. Utilising the ReCiPe impact assessment method, we identified critical environmental impact categories, including fine particle formation, global warming potential, and toxicity. The analysis revealed that the biosynthesis of P(3HO) is the primary contributor to environmental impact, with electricity consumption accounting for approximately 95% of the overall effect. Purification processes significantly increase environmental impact, mainly due to the extra electricity used for freezing, centrifugation and evaporation. The preparation of nanoparticles contributes to the overall environmental impact, but its scale is reasonably differentiated and spans from 0,3% for Ca/Al nanoparticles to 9.9% for Zn/Al-toc variants, respectively. Although producing these eco-friendly polymers involves significant energy consumption, they present a viable long-term alternative to petroleum-based polymers. Specific life cycle management decisions, like recovering substrates, using renewable energy sources, or gaining overall process improvement, could bring significant environmental benefits. Investigated materials show substantial potential in biomedical coatings and active packaging applications.