CSB Probe of DuPont’s Deadly Chemical Leak Finds Process Safety Lapses
An ongoing investigation by the US Chemical Safety Board (CSB) of the 15 November 2014 toxic chemical leak that killed four workers at DuPont’s insecticide plant in La Porte, Texas, has uncovered flawed safety procedures, design problems, and inadequate planning.
Nearly 24,000 lbm of deadly methyl mercaptan escaped in the middle of the night through two valves in a poorly ventilated manufacturing building. In one area of the plant, operations personnel attempted to clear blocked piping. Later, in a different area, two workers opened valves in response to what they believed was a routine, unrelated pressure problem.
The two workers were killed when liquid methyl mercaptan drained from the open valves, filling the room with toxic vapor. One of those workers made a distress call, and two additional workers died responding to that call.