In the cold storage rooms of a former facility for preparing and preserving animal-based products that had since been reconverted into a distribution centre, a watchman hired by the surveillance firm for the site measured and recorded temperatures beyond the tolerance ranges set by the operator. Despite the guideline posted on the measurement recording sheet, the operator was not informed of this measurement noncompliance and moreover no other alarm was activated at this stage.

The remote surveillance firm did not warn the site’s maintenance unit before 4 am the following morning, only after noticing that the alarm connected to the cold storage temperature measurements had tripped. The head of maintenance reacted at 5 am, bringing in a specialised firm contracted to maintain the facility’s installations: repair of the pipe and damaged resistance, reloading of the installation with R22 refrigerant (1,954 kg of which were discharged into the atmosphere). None of the stored food products were not damaged.

This incident resulted from the rupture of a defrosting resistance supply line, which in turn caused an electric arc on an R22 pipe running in an evaporator. The refrigeration installation resistances had been inspected one week prior to the incident.