The present invention relates to a process for the treatment of hazardous waste, the process comprising: (i) providing a hazardous waste; (ii) providing a further waste; (iii) plasma treating the hazardous waste in a first plasma treatment unit, (iv) gasifying the further waste in a gasification unit to produce an offgas and a char material; and (v) plasma treating the offgas, and optionally the char material, in a second plasma treatment unit to produce a syngas, (vi) optionally treating the syngas in a gas cleaning plant, wherein the first plasma treatment unit is arranged to plasma treat at least some of the solid by-products from the gasification unit and/or the second plasma treatment unit and/or the gas cleaning plant.