Fire broke out at noon inside a trailer factory, just as 2 painters were leaving a paint booth to clean their equipment. While bleeding the paint distribution circuits, vapours from the thinner used to clean the installations were ignited by an electric discharge around the electrostatic nozzle on the spraying system. The blaze spread to the liquid solvent and then to both a metal cabinet and the booth’s electrical cables. An inappropriate use of powder extinguishers prevented controlling the outbreak, which reached the booth via the pedestrian access door and spread all the way to the filters. This accident generated thick black smoke. The workshop manager was late in notifying fire-fighters (30 to 45 mins later), who effectively responded with a foam hose. During their intervention, traffic on the street was detoured. The painters sustained slight burns and were hospitalised. This accident was due to the failure to neutralise energy lines around the paint spray gun that was undergoing cleaning. The booth facade, its interior lighting and electrical cabling were all damaged, as were 2 motors and the 2 spraying machines. The facility was restarted 6 days later. All wastes were discharged to a certified treatment centre. Subsequent to this accident, the factory operator adopted a plan to: train workshop technicians in the proper handling of extinguishers; install a new computerised paint distribution system fitted with safety mechanisms to enable, among other things, neutralising energy lines during equipment cleaning phases; and assemble a fire-resistant roof adjacent to each paint booth.