The research on high voltage circuit breakers using SF6 is addressed. The current state of the art in this field is shortly reviewed and future research directions are discussed. These are mainly the radiative energy transport, the understanding and description of ablation processes at the nozzle and contact surfaces, the influence of such vapors on pressure build up and interruption capability, electric breakdown processes, departures from equilibrium, turbulence and the importance of magnetic fields and 3D modelling.