Green chemistry in secondary education: a systematic review of global trends, pedagogical approaches, and implementation challenges

Background Green Chemistry Education (GCE) refers to the integration of green chemical principles – such as waste prevention, atom economy, and the use of safer substances – into science education to promote sustainability and environmental responsibility. In recent years, it has emerged as a key approach for integrating sustainability into secondary science curricula. Systemic challenges – such as curriculum misalignment, limited teacher training, and lack of validated experiments – have hindered broader adoption.Purpose This systematic review aims to examine global trends, pedagogical strategies, curriculum integration models, and barriers in secondary-level GCE. It further seeks to identify research gaps and inform a strategic agenda for future studies and policy development.Methods Following PRISMA 2020 guidelines, 62 peer-reviewed articles (published between 2010 and 2024) were selected from Scopus, Web of Science, ERIC, and ScienceDirect databases. A mixed-method content analysis approach was used to categorize themes such as teaching approaches, student outcomes, regional practices, and systemic constraints.Results (1) Active pedagogies such as project-based learning, inquiry-based instruction, and systems thinking dominate effective GCE models. (2) Student outcomes include increased conceptual understanding, environmental ethics, and science motivation. (3) Implementation success varies by region, with Finland, Germany, and the U.S. showing curriculum integration, while countries like China, India, and Turkey rely on grassroots efforts. (4) Barriers most frequently cited include inadequate teacher training (61%), curriculum misalignment (52%), and limited experimental resources (44%). (5) Research gaps include a lack of longitudinal studies, minimal teacher-focused research, and underrepresentation of non-Western contexts.Conclusion Green Chemistry Education has the potential to foster scientifically literate and environmentally responsible citizens. However, its widespread adoption requires coordinated policy support, inclusive curriculum development, and sustained professional training. This review provides a comprehensive synthesis of international practices, identifies structural and pedagogical barriers, and proposes a future research agenda for advancing GCE in secondary schools worldwide.