Safety is a term referring to lack of threat, guarantee of liquidation or minimizing threats. With regard to drinking water, consumer safety is understood as the probability of avoiding threat resulting from consuming water with quality that is incompatible with applicable normative or lack of water. However, an assumption that the measure of loss of safety is a risk function has become the paradigm. The classical definition of risk implies that it means the possibility of loss, harm with a certain probability. At the same time, there is a term of uncertainty which means lack of certainty and often refers to lack of safety. The main purpose of this paper is to present methods of analysis and risk assessment and the characterization of risk function in probabilistic and fuzzy (possibilistic) aspect.
