Sodium sulfide is also known as odor caustic soda, odor soda, xanthine, and sodium sulfide. Sodium sulfide is an inorganic compound, and pure sodium sulfide is a colorless crystalline powder. Strong moisture absorption, soluble in water. The aqueous solution is strongly alkaline. It can cause burns when it comes into contact with skin and hair. Therefore, sodium sulfide is commonly known as sodium sulfide. The aqueous sodium sulfide solution is slowly oxidized in the air to sodium thiosulfate, sodium sulfite, sodium sulfate, and sodium polysulfide. Since the formation of sodium thiosulfate is faster, the main product of oxidation is sodium thiosulfate. Sodium sulfide deliquesces in the air, carbonizes and deteriorates, and continuously releases hydrogen sulfide gas. Industrial sodium sulfide has a color of pink, brownish red, and khaki because it contains impurities. Specific gravity, melting point, and boiling point also vary depending on the influence of impurities.