Objective: To investigate the circumstances and geographic and temporal distributions of hazardous material releases and resulting human impacts in the United States. Method: Releases with fatalities, injuries, and evacuations were identified from reports to the National Response Center between 1990 and 2008, correcting for data quality issues identified in previous studies. Results: From more than 550,000 reports, 861 deaths, 16,348 injuries and 741,427 evacuations were identified. Injuries from releases of chemicals at fixed facilities and natural gas from pipelines have decreased whereas evacuations from petroleum releases at fixed facilities have increased. Conclusion: Results confirm recent advances in chemical and pipeline safety and suggest directions for further improvement including targeted training and inspections and adoption of inherently safer design principles.