Abstract: The composition of potassium nitrate for agricultural use is different from that of monomer potassium nitrate on physical and chemical properties.Potassium nitrate for agricultural use actually contains calcium，magnesium，sulfate，chloride，moisture，and a variety of impurities and is a multicomponent double salt and solid solution.Experiment results showed that potassium nitrate for agricultural use still cannot burn when ignition point was above 1 000 ℃，so it is noncombustible material itself.The potassium nitrate for agricultural use can react chemically with other reductive agents slowly，no rapid chain reaction will occur and no explosion will happen，so the potassium nitrate for agricultural use is very secure and stable. Furthermore，it has no risk for the human body and the environment. Therefore，the potassium nitrate for agricultural use should be characterized as non-dangerous goods.

Key words: industrial potassium nitrate, potassium nitrate for agricultural use, hazard class, inflammability