Ammonium alginate is a monovalent metal salt of alginic acid. The product is white to light yellow fibrous powder or coarse powder, almost odorless and tasteless, and slowly dissolves in water to form a viscous colloidal solution. It is insoluble in ethanol solutions and hydrogenated alcohol solutions with an ethanol content higher than 30% (wt). It is insoluble in chloroform, ether and acid solution with PH value lower than 3.