AbstractMan has always been existing in an “oecotoxic” environment and he will be existing in the future, though the noxious factors are changing. Today the output of modern chemical industry and its effects on health attract abundant interest.The risks in nutrition derive from imbalanced nutrition, food borne diseases of microbial origin, environmental contaminants, toxicants naturally present in food, food additives, and food allergens, the most important risks seem to be connected with false nutrition and with microbial hazards.The toxic burden of modern man by chemicals can not be judged as the overwhelming nutrition health problem. This burden is only one factor, which —on the genetic background —dynamically interacts with innumerable social, cultural and economic factors, with climate, weather, noise, fatigue and relaxation, with health, functional state, special susceptibility, defense or repair capacity, nutritional situation, water intake, biochronological situation, microecology, coergism of xenobiotics and pharmaca, and others. In this biological system the single potential toxicant plays a quite variable role. The regard of a substance as safe poses a difficult task; the weigh between its toxic properties and its advantages, considering its practical use, should aim at the socially acceptab