Around 7:45 am, fire broke out in a vacuum distillation unit at a refinery. The internal emergency plan was triggered, including the setting of the operator’s crisis room. The Civil Protection Office was notified; external fire-fighters were not called: a crew of 9 onsite fire-fighters intervened and covered the affected zone with foam. Activation of the cooling system at the level of neighbouring installations caused discontinuity in the foam cover, serving to reignite the fire, which took about 10 min to contain. The incident was brought fully under control by 8:25 am. Some 2,000 litres of emulsifier were used, with a 3% application rate. Supply to the leak was cut off around 1 pm, once its origin had been discovered: a flange had come loose on the purge circuit of the pump located at the column base that enables residue transfer under vacuum conditions. The damage caused was minor: a few hoses and heat insulators deteriorated by the heat, and a viscous film (bituminous hydrocarbons) covering a 50 m x 50 m zone. No one was hurt. Operating losses amounted to between €500,000 and €2 million. No direct discharge entered the SEINE River; effluent was recovered in one of the site tanks for subsequent processing so as not to interfere with treatment plant operations. Given the type of product spread, a cleaning of both the sewer and fire water collector pipes was scheduled prior to facility restart. Inspectors requested an accident report to assess damaged equipment and the cause of the leak. The pump carrying the defective flange (on the purge circuit) was being used to replace the main pump, which was undergoing repairs; the flange had loosened due to vibrations on this purge pump.