The Mg2+ cation being the second most abundant cation in seawater and in rocksalt, the potential release of magnesium ions dissolving in brines intruding the deep geological repository is also expected to minimize the geochemical perturbations. MgO has an important place as a commercial plant fertilizer  and as animal feed. An aerosolized solution of MgO is used in library science and collections management for the deacidification of at-risk paper items. In this process, the alkalinity of MgO (and similar compounds) neutralizes the relatively high acidity characteristic of low-quality paper, thus slowing the rate of deterioration. MgO is also used as a protective coating in plasma displays. Magnesium oxide is used as an oxide barrier in spin-tunneling devices. Owing to the crystalline structure of its thin films, which can be deposited by magnetron sputtering, for example, it shows characteristics superior to those of the commonly used amorphous Al2O3. In particular, spin polarization of about 85% has been achieved with MgO versus 40–60 % with aluminium oxide. The value of tunnel magnetoresistance is also significantly higher for MgO (600% at room temperature and 1,100 % at 4.2 K) than Al2O3 (ca. 70% at room temperature). Precautions
Inhalation of magnesium oxide fumes can cause metal fume fever. See also
Calcium oxide
Barium oxide
Magnesium sulfide
Reactive magnesia

Notes
References
External links
Data page at UCL
Ceramic data page at NIST
NIOSH Pocket Guide to Chemical Hazards at CDC
Schilders disease may refer to two different diseases described by Paul Schilder:

Adrenoleukodystrophy
Diffuse myelinoclastic sclerosis