Magnesium oxide

E number E530INS 530CAS 1309-48-4

Used as an acidity regulator — Codex also lists it as anticaking agent.

Magnesium oxide is an anticaking agent, acidity regulator and magnesium fortificant used in powdered foods and supplements.

Where it is and isn’t permitted

Status of Magnesium oxide by jurisdiction. Every jurisdiction this site covers is listed, including those where the substance does not appear.
JurisdictionStatusScope and limitsCitation
United StatesFood and Drug AdministrationPermitted21 CFR 184.1431retrieved 2026-09-07
Codex AlimentariusCodex Alimentarius Commission / JECFAPermitted, with conditions

5 food categories

highest permitted level 10,000 mg/kg

Show every food category
  • 01.2.1.2 Fermented milks (plain), heat-treated after fermentation — GMP
  • 01.5.1 Milk powder and cream powder (plain) — GMP
  • 01.8.2 Dried whey and whey products, excluding whey cheeses — 10,000 mg/kg
  • 12.1.1 Salt — GMP
  • 12.2.1 Herbs and spices — GMP
CXS 192-1995 Table Three, INS 530and 5 further provisionsretrieved 2026-09-07

What it is made from

Produced by heating magnesium carbonate or hydroxide to drive off water and carbon dioxide.

  • Vegan
  • Vegetarian
CAS registry number
1309-48-4
InChIKey
CPLXHLVBOLITMK-UHFFFAOYSA-N
PubChem
CID 14792

Every name it appears under

67 recorded names. A label may use any of them.

E number

  • E530

INS number

  • 530

CAS registry number

  • 1309-48-4

As it appears in regulation

  • Magnesium oxide

Other names

  • Akro-mag
  • Animag
  • Anscor P
  • Calcined brucite
  • Calcined magnesia
  • Calcined magnesite
  • Cyclo/Mag
  • E 530
  • Elastomag 100
  • Elastomag 170
  • Granmag
  • Heavy calcined magnesia
  • Heavy magnesia
  • Heavy magnesium oxide
  • INS NO.530
  • INS-530
  • INSTAMAG
  • KMB 100-200
  • Kyowamag 100
  • Light magnesia
  • Light magnesium oxide
  • Mag ox
  • Magcal
  • Magchem 100
  • Magdose
  • Maglite D
  • Maglite de
  • Maglite K
  • Maglite S
  • Maglite Y
  • Magmilax bolus
  • Magnalax Bolus
  • Magnesa preprata
  • Magnesia
  • Magnesia monoxide
  • Magnesia oxydata
  • Magnesia USTA
  • Magnesii oxidum
  • Magnesium (as oxide)
  • Magnesium oxide
  • Magnesium oxide (MgO)
  • Magnesium oxide, heavy
  • Magnesium oxide, light
  • Magnezu tlenek
  • Magox 85
  • Magox 90
  • Magox 95
  • Magox 98
  • Magox OP
  • Magstar
  • Marmag
  • Megnesium Oxide
  • MVT Bolus
  • Oromag 160
  • Oxide, Magnesium
  • Oximag
  • Oxymag
  • Seasorb
  • Seawater magnesia
  • SLO 369
  • SLO 469
  • Uro-Mag

Systematic names

  • oxomagnesium

Hazard reference values

No reference value for this substance in the sources we hold.

Evidence and how bodies read it

Studies, and the differing conclusions regulators drew from them, are curated by hand rather than machine-read, and none has been written for this substance yet.

Sources for this page

  • ecfr retrieved 2026-09-07
  • gsfa retrieved 2026-09-07

Full licence terms and publisher details on Sources. How this page is built and updated: Method.

Machine-readable:/api/v1/additives/magnesium-oxide.json