E530 (Magnesium Oxide) is an inorganic chemical compound derived from the thermal decomposition of magnesium hydroxide or magnesium carbonate from seawater by precipitation with dolomitic lime as precipitation agent.

It appears as a white, brown or dark powder.

What it is used for and where

Food

Ingredient included in the list of European food additives as E530 with the function of an acidity regulator. It also has the function of an antimicrobial agent (1).

Cosmetics

Absorbent. Absorbs substances dispersed or dissolved in aqueous solutions, water/oil, oil/water.

Buffering agent. It is an iingredient that can bring an alkaline or acid solution to a certain pH level and prevent it from changing, in practice a pH stabiliser that can effectively resist instability and pH change.

Opacifying agent. It is useful into formulations that may be translucent or transparent to make them opaque and less permeable to light.

Medical

It is used in the treatment of constipation where it improved bowel movement, transit time in the colon (2). It is a chemical compound that must be prescribed by a doctor.

Other uses

• high temperature insulation 
• waste remediation
• refractory materials and the glass and catalysis industry

• Molecular Formula     MgO
• Molecular Weight    40.305  
• CAS  1309-48-4 
• UNII    
• EC Number   215-171-9

References_____________________________________________________________________

(1) Almontasser, A., Parveen, A. and Azam, A., 2019, November. Synthesis, Characterization and antibacterial activity of Magnesium Oxide (MgO) nanoparticles. In IOP Conference Series: Materials Science and Engineering (Vol. 577, No. 1, p. 012051). IOP Publishing.

(2) Mori, H., Tack, J. and Suzuki, H., 2021. Magnesium oxide in constipation. Nutrients, 13(2), p.421.