Magnesium oxide
Anti-caking mineral.
- Vegan
- Yes
- Vegetarian
- Yes
What it is
A naturally occurring silicate or magnesium mineral used primarily to prevent powders from clumping together.
How it is used in food
A highly effective anti-caking agent for dry powders.
Commonly found in- Chewing gum
- Spices
- Grated cheese
- Wine clarification
Health and safety
None at food levels. At the much larger doses sold as an antacid or laxative it does have a laxative effect, but food use is nowhere near that.
No safety concern identified at food use levels.
Regulatory status
| Region | Status | Notes |
|---|---|---|
| Australia & New Zealand FSANZ |
Permitted | Permitted under the FSANZ Food Standards Code. |
| European Union EFSA / European Commission |
Permitted | Authorised for food use under EU regulations (Annex II). |
| United States FDA (Food and Drug Administration) |
Permitted | Authorised for food use by the FDA (often GRAS for standard additives). |
Identification on labels
- E-number
- E530
Worth knowing
It is the main active ingredient in many antacid medications (milk of magnesia).
Conclusion
There is no reason to avoid magnesium oxide at the levels used in food. While large doses taken as antacids can cause a laxative effect, the small amounts added to stop clumping in spices or grated cheese are completely harmless. EFSA has identified no safety concerns at food use levels.
References
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Open the appEntry last reviewed 2026-07-28.
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