The material is fed from an opening machine such as Blendomat (Fig. 75, 1). The next device, normally a fan in front of the mixing machine, extracts the material by suction (5). Spark sensor (2) detects smoldering material and metal detector (3) any kind of metal. In either case, active operating flap (4) is opened by a signal from the detector and feeds the material into the receiving waste container, which is equipped with a fire extinguisher device (7) and a temperature sensor (8) to monitor the container (Fig. 75).