| Assay 99.0% min |
| Barium (Ba) 0.002% max |
| Calcium (Ca) 0.002% max |
| Chloride and bromide (as Cl) 0.01% max |
| Color White |
| Form Crystals or fine granules |
| Heavy metals (as Pb) 5ppm max |
| Insoluble matter 0.005% max |
| Iodate (IO3) 3ppm max |
| Iron (Fe) 3ppm max |
| Loss on drying (150 C) 0.2% max |
| Magnesium (Mg) 0.001% max |
| pH of a 5% solution at 25 C 6.0-9.2 |
| Phosphate (PO4) 0.001% max |
| Sodium (Na) 0.005% max |
| Sulfate (SO4) 0.005% max |