White to light yellow flake-like sacly crystal, crystalline powder or graininess, odorless or slight odor. Stowed in the air long time, it absorbs moisture easyly and is oxidized so that it has color. It is easy soluble in water (67.6 g/ 100ml, 20 ℃), 5 % salt solution (47.5 g/ 100ml, room temperature), 25 % sugar water (51g/ 100ml, room temperature). Soluble in propylene glycol (5.8 g/ 100ml), ethanol (0.3 g/ 100ml). pH value is 7 - 8 of 1% aqueous solution. It effectively inhibit putrefactive bacteria and mold. It has become the leading preservatives all over the world because its toxicity is lower than the other preservatives. In acidic conditions, it can sufficiently play a role in antisepsisthe while it's low in neutral condition. Relative density (d2525): 1.363 g/ ml, melting point: 270 ℃ (decomposition).