As NORM industries include a huge variety of chemical and physical processes, ratios among the different chemical elements are altered in relation with natural ratios differently depending of the industrial process. This also includes radioelements, which can present ratios very different in NORM wastes than those observed in raw natural materials. No fixed ratios could therefore be used in advance for every NORM industry, and even within the same industry, slight differences in the raw material of the industrial process would alter those ratios.