At the end of their life cycle, it is expected that many industrial silicone components end up in incineration waste plants. Hence, the issue concerning the risks resulting from the generation of fumes (combustion gas and aerosol) has to be addressed. The aim of our work was to investigate the behavior and fate of nanosilicas from filled polydimethylsiloxane nanocomposites burnt under two different scenarios of incineration. Combustion tests have been performed at lab-scale using a particular tubular furnace and a specific cone calorimeter. The collected fumes (particulate matter and gas phase) have been characterized using various techniques. The results show persistent nanosilica particles, newly produced nanosilica particles in the fumes and in the residues, as well as silicon oxycarbide SixOyCz particles which seem to originate from polysiloxane matrix decomposition.