A central challenge in the environmental and exposure sciences is establishing experimental evidence of the role of chemical exposure in human and environmental systems. Over the past years, non-target analysis employing high-resolution mass spectrometry (HRMS) has been established as one of the key approaches for tackling this complexity. Archived HRMS data affords the possibility of exploiting historical data to rapidly and effectively establish the temporal and spatial occurrence of newly identified contaminants through retrospective suspect screening. Through this exercise, we have established a global emerging contaminant early warning network to rapidly assess the spatial distribution of contaminants of emerging concern in environmental samples through performing retrospective analysis on archived HRMS data. Twelve participants from eleven different countries representing Africa, Asia, Australasia, Europe, and North America participated in assessing the spatial environmental distribution of 309 newly identified contaminants of emerging concern. Archived HRMS data (314 samples) were analysed against a quality assured suspect list, which included novel per- and poly-fluoroalkyl substances, plastic additives including those from tyres, anabolic steroids, mycotoxins, mutagens and selected transformation products of plastics and pharmaceuticals. This collaborative activity's findings will inform the effectiveness of retrospective suspect screening in rapidly assessing the spatial distribution of contaminants of emerging concern. Further, this study aims to identify the critical quality control and quality assurance criteria for retrospective suspect screening based upon this collaborative exercise.