Iron Oxide Brown Chemical Formula: Blended Basic types: 610,663,686,841 CHEMICAL AND PHYSICAL ANALYSIS Fe as Fe2O3≥88.0% Test method ISO1248 Matter volatile at 105OC≤1.0% Test method ISO787-2 Water soluble matter≤0.3% Test method ISO787-3 pH value 3.5 ~7 Test method ISO787-9 Residue on 320mesh≤0.3% Test method ISO787-7 Oil absorption20~30g/100g Test method ISO787-5 Tinting Strength (Compared with Standard) 95~ 105% Test method ISO787-24