Hygienic classifications of pesticides used in the Russian Federation are presented. The classifications cover both technical products and preparative forms of pesticides. Four classes of hazards are distinguished: extremely hazardous, hazardous, moderately hazardous, and slightly hazardous. These four classes are used for classifying general toxicity (peroral, skin, inhalation), cumulative, allergic, teratogenic, embryotoxic, reproductive, mutagenic, carcinogenic effects, and the stability in soil. The class of the hazard is determined on the basis of toxicohygienic evaluation of a pesticide, taking into account a limiting criterion of the hazard.