• • Model-averaging SSD reduced uncertainty from single-function selection, yielding PNECacute values for DEHP and DnBP as low as 1.898×10⁻² and 9.064×10⁻² μg·L⁻¹, respectively, which are more stringent than existing Chinese water quality standards, enabling stricter regulatory thresholds for high-risk PAEs in freshwater.
• • The derived PNECchronic for DMP reached 3.245×10² μg·L⁻¹, indicating a wide margin between acute and chronic effects, which is critical for setting long-term environmental quality criteria and for designing chronic toxicity testing protocols.
• • Risk quotient analysis identified DEHP and DnBP as high short-term risks in typical Chinese surface waters, with HQ values exceeding 1, necessitating priority monitoring and source control in industrial and urban discharge areas.
• • The study integrated ICE and ACR predicted toxicity data for native species, expanding the SSD dataset by up to 40% for data-poor compounds like DIDP, thereby improving the statistical robustness of PNEC estimates for emerging contaminants.