A violent explosion and fire occurred in a dye production plant, injuring 9 employees 2 seriously burned. A chemical reaction was ongoing in a 40 years old, 7 500 L carbon steel reactor (2.7 m high). Workers had turned on the steam supply to the reactor at 7:40 p.m, beginning what they assumed would be a routine six to eight-hour production run of a dye used to tint petroleum fuel products. But within less than half an hour, a runaway reaction had started and the temperature inside the reactor rocketed. Despite the action of the chief operator who launched the cooling system, the temperature topped 176°C, at which chemicals inside the kettle would begin to decompose. Liquid and gas began venting from the top of the rumbling kettle ; workers rushed for exists.

At 8:18 p.m., the plant shook as accumulated pressure blew off the 45 cm metal hatch that was clamped to the top of the kettle. The kettle was lifted from its moorings and driven into the floor below. A fiery stream of gas and liquid erupted through the roof of the building, raining down chemicals onto the surrounding community.

Residents in a 100 city-block area were confined to their homes, voluntarily sheltering in place for up to 3 hours while officials evaluated health risks. Firefighters and workers in neighbouring businesses reported throat, eye, and skin irritations consistent with chemical exposure.

The CSB investigated the case and found that the operator had not adequately evaluated or controlled the hazards of the reactor; as a result, the reactor was not provided with sufficient cooling capacity or adequate emergency shutdown or venting systems. Furthermore, 2 process changes were introduced without safety analysis in 1990 (adjunction of a reactant in one shot instead of 4) and 1996 (batch volume increase) and thus exacerbated the risks of a runaway reaction, as it became difficult to keep the temperature within the narrow safe operating range. Temperature-control problems occurred in eight of the 32 previous batches, but none of those “near-misses” events had been analysed. Finally, the operator did not provide its personnel with adequate instructions for operating safely. The operator was advised to revalidate its analyses of the hazards of all reactive chemical processes, to revise operating procedures and training, install any needed pressure relief and emergency shutdown equipment, and establish a program to investigate any unsafe process deviations in the future. The Board further recommended that parent corporation establish a program to share reactive chemical safety information more widely within the company.