The complex hygienic assessment of a large enterprise of chemical profile as a source of the chemical and physical effects on the environment and human health has been given. Modernization of the production with the introduction of modern technologies, effective gas- powered dust collector units was found to permit to reduce emissions by 20%, diminish the levels of atmospheric air pollution to the normative values, health risks--to acceptable. According to the research after the reconstruction of the plant the possibility to move it from 1 to 2 danger class with reduction in size of sanitary protection zones in 2 times (from 1000 to 500 m).