The alert for the fire at the Camarc company, located in the industrial zone of Mata, in Mansores, was given around 2:23pm.
A GNR source told Lusa that the fire caused a lightly injured person who was transported to Santa Maria da Feira Hospital.
According to the same source, the factories located in the vicinity of the fire have also been evacuated.
The Judicial Police have been called in to investigate the causes of the fire.
According to the website of the National Authority for Emergency and Civil Protection, at 3:10pm were on site 68 operatives, supported by 28 vehicles.