Constituents Hydrated lime Unit Ca(OH) 95 minimum % CaCo 5 maximum % MgO 2 maximum % AS 5 maximum Mg/kg Lead as Pb 5 maximum Mg/kg SiO2 0.3 maximum % Fe2O3 0.5 maximum % Al2O3 0.5 maximum % Water Content 2 maximum % Fineness : Minimum 90% passing through 200 mesh sieve (75 micron)