While preparing 10 600 L of
a 25% aqueous solution of sodium
chlorite (NaClO2), the solid salt was spilled and not cleaned
up promptly. Combustible materials, including cardboard sheets and
polypropylene fabric, became contaminated with solid sodium chlorite.
Subsequently, a spark, initiated by inadvertently striking metal drum
sealing rings together, ignited the oxidizer-contaminated combustible
materials. The fire spread to a polypropylene bag containing 800 kg
of sodium chlorite. The contents of the bag detonated causing one
fatality, two serious injuries, and extensive property damage. The
incident was thoroughly investigated, leading to the conclusion that
a series of process safety management failures occurred which created
the conditions driving the incident. The investigation is summarized
and discussed, with an emphasis on the investigation procedures used
to support the root cause analysis and conclusions. Recommendations
are provided to help prevent similar incidents.