 In spite of sophisticated technology, it may happen that higher emission values are reached due to inhomogeneous fuel (waste composition), especially in the phases of start up, shut down and malfunction of a plant.The legally permitted emission levels usually are far above the actual emissions of pollutants if the emissions over a period of one year is considered.These isolated instances of exceeding the limits have no effect on public health since even these higher values are usually still within the limits permitted for other technical or chemical plants.