A multi-method integrated weighting framework for biosafety risk assessment of infectious substances

Biosafety risk assessment of infectious substances in cross-border movement is essential for preventing biosecurity threats and supporting regulatory decision-making. However, existing approaches often rely either on subjective expert judgment or purely objective data, making it difficult to effectively integrate heterogeneous information sources. This study proposes a multi-method integrated weighting framework for cross-border biosafety risk assessment by combining the Fuzzy Analytic Hierarchy Process (FAHP), Principal Component Analysis (PCA), and an integrated TOPSIS-GRA evaluation model.In the proposed framework, FAHP and PCA are used to derive subjective and objective indicator weights, respectively. The discrepancies between different weighting results are explicitly characterized, and a constrained deviation-minimization optimization model is constructed to reconcile heterogeneous weighting information and obtain a combined weight vector under normalization constraints. The integrated TOPSIS-GRA model is then applied to quantify biosafety risks by jointly considering the distance from ideal solutions and grey relational similarity. A scenario-based case study on cross-border infectious substances demonstrates that the proposed framework improves the consistency, robustness, and interpretability of biosafety risk evaluation. The results indicate that the proposed approach provides a structured and reproducible tool for multi-criteria decision-making under uncertainty and offers practical support for biosafety management.