In December of last year, the National Transportation Safety Board (NTSB) and the US Chemical Safety and Hazard Investigation Board (CSB) stated that the two agencies had signed a Memorandum of Understanding providing that the NTSB would be the lead agency for investigating transportation-related accidents involving the processing, handling, or storage of a chemical substance that result in death, serious injury, or substantial property damage. The CSB is an independent, scientific investigatory agency (not a regulatory or enforcement body) created by the Clean Air Act Amendments of 1990, whose mission is to promote the prevention of major chemical accidents at fixed facilities.