Magnesium oxide is the starting material for the production of sinter magnesia for refractory applications as well as for fusion magnesia which finds application as insulating material in the electric heating technique. In order not to lower the melting point, no SiO₂ should be present in MgO-containing formulations. Chemical data for magnesium oxide are given on a separate page.  Magnesium oxide cannot be used in slurries or coatings based on aqueous systems, since it tends to form hydrates. As an alternative, solvent-containing systems should be taken into consideration, e. g. on alcohol base.