Chemical Analysis Magnesium Sulphate (MgSO4) 48.3% Min Magnesium Sulphate (MgSO4, 7H20) 99.0% Min Magnesium Equivalent 9.7% Min Magnesium Oxide (MgO) 16.4% Chloride (Cl) 600 ppm max (0.06%) Water Content (wt.loss @ 450°C) 51.0% Sulfur 12.7% Min Lead 10mg/kg Max Iron 20mg/kg Max