The development of the chemical industry in the USSR, the introduction of new chemicals in all sectors of the national economy pose the task of occupational hygiene to ensure working conditions that completely exclude the development of occupational poisoning and disease. An important role in this belongs to industrial toxicology .. In recent years, the number of laboratories and individuals has increased significantly. who are engaged in the study of the toxic properties of chemical compounds and the justification of hygienic recommendations (the establishment of maximum permissible concentrations, personal protective measures, etc.) d. ) when working with them. The manual presents the basic concepts of toxicology, the principles of establishing the maximum permissible concentrations in the air of production facilities. A description of methods of seeding experimental animals with an assessment of the acute effect of the poison and the cumulation coefficient. A special part is devoted to the description of general methods of studying the functions of organs and systems in order to establish the threshold of action (functions of the nervous and cardiovascular system). Liver and Kidney Functions , Determination of the threshold of irritant action , State of Energy Processes , blood and blood formation systems). Particular attention is paid to methods of quantitative study of the reproductive function of females and males when exposed to chemicals, the study of carcinogenic and sensitizing properties of products, immunological and microbiological methods used and toxicology.