Environmental risk is defined as a harm to itself, i.e. only to such subject that comes into the contact with the risk factor. Risk assessment is determination of the type and degree of hazard represented by specific factor, further determination, in which extent were, are, or can in the future be the individual populations exposed and characterization of the existing or potential risks resulting from the findings listed. The own process of the risk assessment itself contains several steps. The first step of the risk assessment and hazard identification is the interdisciplinary, team issue with dominating position of the toxicology and epidemiology branch. Subsequent step of the risk assessment is determination of the dose – response relationship, when we distinguish the effect and response that is the measureable rate of the same. The third step of the risk assessment is the own Exposure Assessment, which is a part of the risk assessment consisting of the given population characteristics and size of the exposure concentration and frequency, resp. exposure duration. The fourth and the final step of the risk assessment is the Risk Characterization involves the synthesis of the data obtained within the previous steps. It leads to the determination of probability, with which the human body will suffer some possible injuries. Main part is the balance and critical assessment of all approximations, extrapolations and uncertainties that occurred either deliberately or at random within the previous steps.