An explosion occurred on the cryogenic nitrogen storage of a plant producing paints and varnishes. In the morning , the plant called for a maintenance intervention of a technician from the subcontractor operating the nitrogen storage because they were encountering difficulties with the production. Short after the technician arrived on site, the nitrogen gas buffer tank exploded violently : it lifted from its anchor bolts, rocketed into the air and landed upside down on the ground, killing the technician and 3 other employees.

The top part of the buffer capacity was found upside down near the bottom part and the water of the vaporization pool was found frozen. The accident happened on a 500 m3/h nitrogen plant equipped with a nitrogen vaporization system and a buffer capacity at 9 bar pressure. The vaporization system, started in 1996, consisted in a liquid nitrogen storage and a water bath type vaporizer with water supplied by the customer plant.

Cold gaseous or liquid nitrogen entered into the buffer tank made of carbon steel, which did not withstand the cold and bursted (due to cryogenic embrittlement of metal).

The international firm that provided nitrogen plant revised all installations of the same type (worldwide) and modified customer contracts to take into account : the estimated flow rates and use patterns, the design performance of the vaporization system, the emergency response in case of non normal situation, the selected low temperature protection system as well as customer training.