Contamination with radioactive material may occur as an accident in the works of medicine, industry or research institutions. Seriousness of the resulting situation depends mainly on the radioactive isotope involved. Usually, there are no major acute health effects (not considering nuclear reactors accidents), but in long term can cause malignancies, leukaemia, genetic defects and some anomalies. The most common is superficial contamination; however, the radioactive material can enter the body and be retained by cells of target organs, injuring directly and permanently sensitive parts of the body. Therefore, rapid intervention is very important to remove the radioactive material without spreading it to neighbourhood area. Work must be done in a specially prepared area and personnel on duty should wear protective clothing. For external decontamination general cleaning techniques should be used, which do not require the use of chemicals. For internal decontamination, it is required to use specific agents, according to assumed or known contaminant, as well as physiological intervention to enhance elimination and excretion of contaminant element