... , explosives, electroplating, tanning, ceramic, building materials, crystals and medicine. Industrial Grade Food GradeUnitFine GradeTECHNICAL GRADEFIRST GradeRegular GradeUnitStandardPurity(as K2CO3 ) % ≥99.099 ... .0003Heavy Metal(as Pb) % ≤0.002standardGB/T 1587-2000HG2452-93 Technical Grade of Potassium Carbonate