Toroidal magnetic containment attempts to confine the reaction to an area not in direct contact with the machine. A longterm problem for any eventual working device will be that neutrons are released by fusion and aren't confined by electric or magnetic fields. Neutrons degrade whatever they run into, over time leaving the tokamak (for example) radioactive. There's also a need for care taken to select the materials, to avoid the high temps and neutron bombardment from starting an uncontrolled fission reaction. Yeah, I want a fusion reactor in my house. :^)
Thanks for the answer Civ...