Recommended Occupational Exposure Limits for GMA Using Benchmark Dose and Bayesian Model Averaging.

Introduction: Glycidyl methacrylate (GMA) is a widely used industrial polymerization material. Current occupational exposure limits (OELs) for GMA in China show significant disparities compared to those established by international regulatory bodies, including the United States, the European Union, and Japan. A comprehensive revision of GMA exposure limits is crucial for ensuring optimal worker protection. Methods: This investigation analyzed data from a 104-week inhalation carcinogenicity study of GMA in mice conducted in Japan. This study identified statistically significant pathological endpoints and employed benchmark dose (BMD) analysis to evaluate meaningful endpoints, focusing on those with the lowest benchmark dose lower bound values. The final recommendations were optimized using Bayesian model averaging (BMA) methodology to establish appropriate OELs. Results: Our analysis recommends a time-weighted average allowable concentration of 0.01 ppm for GMA, which aligns with international standards established by the European Chemicals Agency (0.016 ppm), Japan Society for Occupational Health (0.012 ppm), and American Conference of Governmental Industrial Hygienists (0.01 ppm). Conclusion: The combined application of BMD and BMA methodologies represents a scientifically robust approach for deriving points of departure in risk assessment. These evidence-based OELs are essential for effective occupational hazard management and worker health protection.