... powderSodium Hexametaphosphate Industrial Grade Total phosphate, as P2O5 68.0% min. Inactive phosphate, as P2O5 7.5% ... Hexametaphosphate Food Grade Total phosphate, as P2O5 68.0% min. Inactive phosphate, as P2O5 7.5 ... Qualified Water insoluble 0.0 6% max. Arsenic, as As 0.0003% max. Fluoride, as F 0.003% max. Heavy ... metal, as Pb 0.001% max. Iron, as Fe 0.05 ...