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December 12, 2014

Update on Dupont incident

Excerpt from Written Testimony Submitted by U.S. Chemical Safety Board Chairman Rafael Moure-Eraso to the Joint Committee: Senate Committee on Environment and Public Works and the Senate Committee on Health, Education, Labor, and Pensions hearing entitled, "Oversight of the Implementation of the President’s Executive Order on Improving Chemical Facility Safety and Security”:
 
"The most recent example is the tragic chemical accident at the major DuPont chemical plant in La Porte, Texas, just east of Houston.  On November 15, 2014, there was a release of methyl mercaptan, a highly toxic and volatile liquid, which DuPont itself has estimated at 23,000 pounds – a very significant quantity.  Odors of the chemical were reportedly discernible many miles from the plant.  Four workers – including operators and would-be rescuers – perished inside the methomyl-production building where the release originated.
DuPont is certainly no “outlier.”  In fact, DuPont has long been regarded as one of industry’s leading lights in safety, and it markets its safety programs to other companies.  What happened last month, however, was the fifth release incident at a DuPont facility that the CSB has investigated since 2010, and three of these had associated fatalities.  While the CSB investigation remains underway in La Porte, some preliminary facts are already emerging.
The incident occurred following an unplanned shutdown of the methomyl unit due to inadvertent water dilution of a chemical storage tank several days earlier.  Efforts were underway to restart the process, but problems occurred including plugged supply piping leading from the methyl mercaptan storage tank.  As efforts were underway to troubleshoot these problems, it is likely that methyl mercaptan (and possibly other toxic chemicals) inadvertently entered the interconnected process vent system inside the building.  The release occurred through a valve that was opened as part of a routine effort to drain liquid from the vent system in order to relieve pressure inside.  We found that this vent system had a history of periodic issues with unwanted liquid build-up, and the valve in question was typically drained directly into the work area inside the building, rather than into a closed system.  In addition, our investigators have found that the building’s ventilation fans were not in service, and that the company did not effectively implement good safety practices requiring personnel to wear appropriate personal protective equipment (PPE) that was present at the facility.  Appropriate PPE would include equipment, such as supplied air respirators, for workers performing potentially hazardous tasks inside the building.
In summary, this was a complex process-related accident with tragic results.  It gives rise to a number of design and organizational safety concerns.  Its occurrence – taken along with other major accidents afflicting large and small corporations – underscores the need for some systemic reforms.  It would be a serious and tragic mistake to consider each of these accidents as just another isolated event, reflecting only the limited practices of a small group of people operating outside regulatory scrutiny.  If it can happen at DuPont, I would submit it can happen anywhere."


Read the complete CSB written testimony to joint committee from which above excerpt was taken in this link

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