Manganese(II) oxide that the Mn ions form a face centered cubic magnetic sub-lattice where there are ferromagnetically coupled sheets that are anti-parallel with adjacent sheets. Manganese(II) oxide undergoes the chemical reactions typical of an ionic oxide. Upon treatment with acids, it converts to the corresponding manganese(II) salt and water. Oxidation of manganese(II) oxide gives manganese(III) oxide. MnO occurs in nature as the rare mineral manganosite. Commercially it is prepared by reduction of MnO with hydrogen, carbon monoxide or methane, e.g.: MnO can also be prepared by decarbonation of the carbonate: This calcining process is conducted anaerobically, lest MnO form. An alternative route,
Manganese and copper. However, exposure to manganese dusts and fumes should not exceed the ceiling value of 5 mg/m even for short periods because of its toxicity level. Manganese poisoning has been linked to impaired motor skills and cognitive disorders. The permanganate exhibits a higher toxicity than the manganese(II) compounds. The fatal dose is about 10 g, and several fatal intoxications have occurred. The strong oxidative effect leads to necrosis of the mucous membrane. For example, the esophagus is affected if the permanganate is swallowed. Only a limited amount is absorbed by the intestines, but this small amount shows severe effects