Environmental Fate and Phytotoxicity of Cosmeticrelevant Carbonbased Nanomaterials

The rapid incorporation of carbon-based nanomaterials (CNMs) such as graphene, carbon nanotubes (CNTs), and carbon nanofibers (CNFs) into cosmetic formulations raises questions about their environmental fate and ecotoxicological risks, including phytotoxic effects on terrestrial plants. This paper synthesizes current evidence on (i) environmental pathways and transformation processes that CNMs may undergo from consumer use to environmental release, (ii) mechanisms of phytotoxicity and plant uptake, translocation, and metabolic disruption, and (iii) knowledge gaps and risk-management strategies for a safe-by-design approach in cosmetic nanotechnology. We integrate findings from ecotoxicology, environmental fate studies, plant biology, and cosmetic nanomaterial literature to present a cohesive framework for assessing and mitigating potential ecological impacts. Our synthesis highlights that while CNMs can exhibit beneficial properties in products, their environmental behavior is governed by material form, surface chemistry, aggregation state, and matrix interactions, which in turn modulate phytotoxicity. We identify priorities for standardized exposure scenarios, harmonized analytical methods, and lifecycle assessment to support regulatory decision-making and responsible innovation in nanocosmetics.