Emerging flame retardants in the marine environment: A comprehensive review of occurrence, fate and analytical challenges

Emerging flame retardant (EFR) pollutants are ubiquitous in marine environment due to their extensive applications, and capacity for persistence and long-range atmospheric transport. The accurate analysis of EFRs in marine matrices remains challenging due to the inherently low sensitivity and selectivity in complex matrices, matrix-induced signal suppression, limited analytical throughput, and the lack of robust non-target screening protocols. This review provides an integration of recent methodological breakthroughs, encompassing sensitive instrumental approaches and innovative extraction and purification techniques for EFR detection in marine multi-matrix. The environmental occurrence and process of EFRs highlight that the roles of particle-mediated transport, plastic debris leaching, and photochemical degradation co-govern the fate of EFRs in marine environments. Furthermore, the review critically examines the ecological risks of EFRs, focusing on their bioaccumulation-driven toxicity, trophic magnification in marine food webs, and the potential for ecosystem destabilization. Mechanistic insights into photochemical transformation pathways are summarized, highlighting the formation of persistent and more toxic products that raise risks of chronic exposure and ecological disruption in marine environment. It provides a scientific foundation for regulatory agencies to assess marine environmental risks and implement targeted mitigation strategies. Future research should focus on quantifying the ecological impacts of EFRs to support a more effective monitoring and management framework.