The purpose of the article is to present the most important threats to national security caused by road transport of selected hazardous materials. The paper deals with the issues of classification of dangerous materials and means of transport used for this purpose as well as legal acts in force. The State Fire Service's tasks and activities during road accidents involving dangerous goods has been illustrated. On the basis of the statistical data analysis, reports and legal acts, a causal analysis of accidents involving hazardous materials in Poland was made (KiM system).