(96e) Reactor Explosion at the XYZ Chemical Company

A few years ago, there was an explosion in a reactor at the XYZ Chemical Company that resulted in the death of two workers. The reactor was a block copolymerization reactor where butadiene and styrene monomers were added in a semi-batch manner. The heat of reaction was removed by means of evaporation of a solvent within the reactor. The incident occurred when the reactants were not added in the sequence or quantity desired. The resulting runaway reaction overpressurized the reactor system and caused an expansion joint to rupture. The hydrocarbons released formed a vapor cloud that exploded, causing the death of two workers and significant damage to the facility.

The contributing causes of the incident included most of the PSM elements: lack of information about the hazards of the chemicals in the process, lack of information about the equipment in the process and inadequate equipment, inadequate or no PHA, inadequate training, confusing operating procedures, failure to use management of change procedures, failure to perform a pre-startup safety review, failure to have an adequate contractor safety program and failure to investigate previous near misses and incidents and take corrective actions. The root cause was that the XYZ Chemical Company chose to have an inadequate PSM program; they chose to do no more than they needed to do to appear to have a PSM program.