Phosphated distarch phosphate is a variation of distarch phosphate, a chemically modified starch. It can be derived from wheat starch, tapioca starch, potato starch or many other botanical sources of starch. It is produced by replacing the hydrogen bonds between starch chains by stronger, covalent phosphate bonds that are more permanent. It is manufactured by treating starch with sodium tripolyphosphate (STPP) and sodium trimetaphosphate (STMP), or phosphoryl chloride (POCl3). Phosphorylated cross-linked starches is a category of modified food starches within the U.S. Code of Federal Regulations. Starches treated with STMP and STPP must not exceed 0.4 percent phosphorus as residual phosphate.