The federal government does not know how many U.S. chemical facilities store ammonium nitrate, the fertilizer that detonated during a warehouse fire in West, Texas, last year, killing 14 people, the Government Accountability Office says (GAO-14-274). Congressional investigators attribute the incomplete picture to limited information sharing among federal agencies, poor coordination with states, and industry reporting exemptions. Without improved monitoring, GAO warns, federal agencies “will not know the extent to which dangerous conditions at some facilities may continue to exist.” The report notes that 1,345 facilities in 47 states have informed the Department of Homeland Security for security purposes that they store ammonium nitrate. But a spot check of state records by investigators indicates that the federal database is missing as many as two-thirds of the nation’s storage sites for the substance, GAO says. It recommends that federal agencies improve data sharing, OSHA and EPA consider expanding decades-old safety regulations to cover ammonium nitrate, and OSHA conduct outreach to the fertilizer industry and target high-risk facilities for inspection.