Explosion of hydrogen and sodium borohydride in a pharmaceutical plant

The loss of control of a reaction caused a fire in a pharmaceutical plant caused a reaction runaway and the rupture of a 6 m³ reactor. A cloud containing sodium borohydride and hydrogen was emitted.
The production manager evacuated the installation. When the cloud reached electrical equipment, an explosion occurred. The cooling circuit was damaged. The thermal oil leaked and ignited. The fire spread to a large part of the plant.
Firefighters intervened. The water of extinction was confined in basins. Storage tanks that were not affected by the fire were emptied. During the accident, 30 t of oil burned. 50% of the installations were destroyed, representing a damage of 12 M €.

The runaway of the reaction was due to a change in the reaction temperature. In order to increase reaction efficiency, it had been lowered from 50 ° C to 20 ° C. The accident occurred during the first production under these conditions. No risk analysis of this operative change had been made beforehand. The standard procedures of the group to which the plant belongs did not take into account the risk of runaway exothermic reactions.

INITIATING cause was the a reaction runaway cause explosion of the reactor.
Root cause was the decision to run the reactor at a lower temperature than the one used till that moment, without an risk assessment.

unspcified chemical reactor

Reaction temperature in the reactor containing NABH4 and H2 was lowered from 50C to 20C.

During the accident, 30 t of oil burned. 50% of the installations were destroyed, representing an damage of 12 M €.

After the accident, the operator modified the Management of Change procedures.
This event was at the origin of an evolution of the regulations to integrate this experience feedback.