A major explosion at the Chevron refinery in Richmond California in August 2012 resulted in no fatalities and led 15,000 people in the community to seek medical attention. That event spurred the Governor to establish a Task Force to examine what steps should be taken to improve refinery safety in the State. The RAND Corporation was asked by Christine Baker, the Director of the Department of Industrial Relations, to investigate several issues in order to inform the Task Force’s discussions. This memo is the response to that request. It has 3 parts. The first summarizes information about different regulatory models and provides some recommendations about how to proceed in adopting new models. The second briefly summarizes suggestions about the role that measures of “leading indicators” can play in future regulation. The third reviews what existing measures tell us about changes over time and comparisons across continents.