Cutting and platinisation work was carried out at an oil terminal to remove a dead leg from a pipe used to supply a storage tank. Before starting the job, the workers had used an explosimeter but found nothing unusual. A specialist firm had cleaned out the pipe beforehand. Thinking that the pipe was empty, the workers did not place a spill containment tray underneath it. However, upon opening a flange, a mixture of water and hydrocarbons began spilling out onto the ground and was ignited by a spark. One worker used a fire extinguisher, but accidentally caused the fire to spread along 5 m. The site’s siren was activated, but the internal emergency plan was not implemented. The onsite fire-fighters extinguished the fire with a monitor mounted on a fire engine. A scaffolding, electrical wiring and thermal insulation were damaged by the fire. The inspection authorities for classified facilities went to the site in the following days.

The operator changed its procedures. From now on, drip trays are to be systematically used during jobs. Measurements are to be taken with an explosimeter at ground level (and not just at breast height) before each job. Vertical protective screens are to be set up when cutting pipes. Lastly, pipes are to be welded outside ATEX zones and no longer at pipe level.

During a visit on 15 May, the inspection authorities for classified facilities also found that the SMS implemented at this upper-tier Seveso site had not been updated after the recent change in owner.