<p>The uncontrolled recycling and disposal of e-waste in informal sectors release complex mixtures of halogenated flame retardants (HFRs) into the environment. Yet, comprehensive data on their environmental behavior and combined health impacts remain limited, particularly in developing regions. This study presents the first comprehensive assessment of 18 HFRs, comprising 8 legacy polybrominated diphenyl ethers (PBDEs) and 10 alternative HFRs (AHFRs), in soils from 18 recycling centers and 7 waste disposal sites (DS, 6 dumping sites and 1 landfill site) in a developing region. The median (min-max) concentrations (ng/g) of ∑8PBDEs and ∑10AHFRs were significantly (<i>P</i> &lt; 0.05 for all) higher in the recycling center’s soil [5952.78 (1021.91-10677.34), and 2911.31 (898.70-5357.68)] compared to disposal sites [282.45 (241.89-707.84) and 97.29 (67.02-238.34)], highlighting the differential fate of e-waste contaminants. Spatial and multivariate analyses revealed that e-waste management activities, notably acid digestion, open burning, shredding, and dismantling as key activities driving HFR release. Non-carcinogenic risks ranged from 4.64 × 10^− 3 to 2.28 × 10^− 1, while carcinogenic risks were between 3.51 × 10^− 10 to 3.48 × 10^− 8, all below acceptable thresholds. While PBDEs dominate current contamination, AHFRs are emerging and may increase with continued informal e-waste handling. These findings provide baseline data for tracking the evolving composition of flame retardants in informal e-waste management in a developing region and contribute to global efforts to refine emission inventories and risk management strategies.</p> Graphical Abstract <p></p>