1.Magnesium Sulphate Hepta Powder Food Grade. MgSO4.7H2O 99% As 2ppm Cd 10ppm Pb 25ppm Fe 20ppm Packing:25kg pp bags. 2.Magnesium Sulphate Hepta Powder Tech Grade. MgSO4.7H2O 98.64%. Cl: 0.013%. Fe: 0.002%. Heavy Metal: 0.001%. As: 0.0003%. Loss on Ignition: 49.5%. Packing:25kg pp bags.