The toxicological and hygienic estimation of the contents of nitrates in the basic vegetable cultures (beet, carrots, potato etc.) is given. Is shown, that nitrates, contained in the increased amounts in the aforesaid cultures are not indifferent for human and animals organism. At a unbalanced diet of cattle use of forages with the increased contents of nitrates can result in occurrence them in livestock products. The hygienic regulation of permissible concentrations nitrates in some products should be carried out with an allowance fo structure of nutrition of the population, contents nitrates in drinking water, and also other factors capable to influence on formation of nitrate body burden on the population and to aggravate effect of nitrates action.