This Decree establishes that emergencies shall be classified according to the causes (sources) of their occurrence and depending on the number of people affected in these situations, the amount of material damage and scale (boundaries of zones). Emergencies are subdivided into local, national and cross-border. Emergencies of technological character include: (a) transport accidents and disasters; (b) accidents at hazardous chemical facilities; (c) accidents at fire-explosive facilities; (d) accidents on energy and utility systems; (e) sudden collapse of buildings; (f) accidents associated with the use or storage of radioactive and other hazardous and environmentally harmful substances; and (f) hydrological disasters and accidents, including flooding. Natural emergencies include: (a) geological hazards; (b) hydrometeorological hazards; and (c) epidemiological, epizootic and epiphytotic emergency situations. Environmental emergencies include: (a) situations associated with changes in the state of the land (soil, subsoil); (b) situations associated with changes in the composition and properties of the atmosphere (air environment); and (c) situations associated with changes in the state of the hydrosphere.