In a mechanical transmission components manufacturing plant, a metal dust explosion occurred followed by an outbreak of fire at around 4.15 pm during maintenance on an industrial vacuum cleaner used for cleaning the company’s metallisation chambers used for applying aluminium, tin and copper alloy in the form of molten metal to mechanical components. The employee whose face and arm were burned was taken to hospital; he was discharged the same day. The staff extinguished the fire within 10 min using extinguishers. Alerted at 4.30 pm, upon their arrival, 15 min later, the public emergency services checked that there were no residual hot spots in particular in the dust collection installation for the discharge from the metallisation chamber located close to the scene of the accident. The inspection authorities for classified facilities carried out an investigation the same day. The suction system used for cleaning the chambers consisted of a pipe several metres long connected to a metal drum with a capacity of around thirty litres, which was connected by a second pipe to an industrial vacuum cleaner. This equipment initially designed to recover chips, in principle, is used only to fill the drum. The explosion occurred in an operating vacuum cleaner connected to a suction system, when cleaning another vacuum cleaner which was switched off. According to the operator, an electrostatic phenomenon may have caused ignition of the explosive atmosphere due to the presence of aluminium powder inside the device. The inspection authorities for classified facilities requested suspension of the use of this type of equipment for cleaning inside and in the surrounding areas of metallisation chambers as well as for other work stations that are likely to generate dust. The operator also had to send a report on the circumstances, causes and consequences of the accident and indicate the provisions made for the cleaning in order to prevent such an event from happening again.