The remote telesurveillance of the refrigerating installations of a meat preparation plant raised an alarm at around 8.30 pm indicating a compressor operating anomaly causing the chiller unit concerned to be automatically switched over to safety mode.

At around 9.50 pm, the maintenance service contacted checked the installation’s operating parameters and circuits, then restarted the compressor at shutdown. The compressor’s housing then violently exploded upon startup, spraying oil and NH3 over the maintenance officer. The employee closed a main valve and quickly left the machine room. This employee was experienced, but did not have any special safety equipment to intervene, which simply involved resetting the compressor. Having received burns to the mouth and legs, he was to undergo x-rays and a few days of oxygen therapy.

Firefighters intervened shortly after and isolated the compressor; 10 kg of NH3 were lost. The forced ventilation system in the room had worked correctly, only generating a small amount of air pollution. As a precaution, the gendarmerie (French military police) set up a safety perimeter and 15 residents left their homes for 4 hours.

The installation was kept shut down pending the visit of a refrigeration technician a few days later. This technician did not detect any alloy or circuit faults. This was the 2nd incident in a few months on this installation which was placed back in operation, but was due to be replaced in 2007.