In this communication brief, the authors outline an important challenge, particularly distinguishing between the plastic substitutes (nature-based non-plastic materials) and plastic alternatives (better plastics in terms of biodegradability and compostability, but still plastic traces are available) to avoid existing ambiguity. Thus, clarifying the terminology surrounding plastics, bioplastics, and biopolymers is not merely a semantic exercise; it is foundational for effective policy, consumer transparency, and sustainable material innovation.

This concept offers a corrective to that confusion through a structured classification matrix and the introduction of the notion of Zero-Trace Plastic, a forward-looking policy proposition that links material design to real-world degradation outcomes. Unlike current certifications, ZTP calls for environment-specific performance thresholds and system-wide traceability, ensuring that materials labelled as “sustainable” genuinely align with ecological safety across marine, soil, and composting contexts.