| Identification | Positive for calcium | 
| Assay, percent CaCO3 | Not less than 98.0 Not more than 100.5 | 
| Acid Insoluble Substances, percent | Not more than 2.5 | 
| Arsenic (as As), mg/kg | Not more than 3 | 
| Fluoride, percent | Not more than 0.005 | 
| Heavy Metals (as Pb), percent | Not more than 0.002 | 
| Lead, mg/kg | Not more than 3 | 
| Loss on Drying, percent | Not more than 2.0 | 
| Magnesium and Alkali Salts, percent | Not more than 3.5 | 
| Mercury, mg/kg | Not more than 0.5 | 
| Median Diameter, microns | 15 |