Thick white smoke filled a building at a machine and equipment manufacturing plant at around 7 pm. The safety manager evacuated the staff, cut off the power supply to the installations and alerted the emergency services. The incident resulted in the exothermic polymerisation of 300 g of resin. Indeed, a technician had prepared this resin in the afternoon in order to supply a carbon fibre winding machine, but considered his preparation to be non-compliant. He then left it in the workshop without taking any further action and forgot to neutralise it. The emergency services examined 10 employees exposed to the smoke on site: no one needed to be hospitalised. Following this accident, operations using these resins were suspended. The inspection authorities for classified facilities asked the operator to list and identify the high-risk areas of its establishment.