Definition of major hazard sources. The Safe Production Law promulgated in China in 2014 defines a major source of danger as a unit (including site industry facilities)in which the quantity of dangerous goods produced, transported, used or stored for a long period of time is equal to or exceeds a critical amount dangerous item unit critical amount Highly toxic chemicals and other Production, storage facilities The minimum amount of a chemicals that are harmful to humans facilities or sites involving hazardous source that constitutes facilities and the environment, such as hazardous chemicals are a hazardous source of a certain poisonous, corrosive, explosive, divided into production units type or class of hazardous burning, and combustion-supporting and storage units chemicals1 2 3 Definition of major hazard sources: