E504I - Magnesium carbonate

At a glance

Here are the quick facts about magnesium carbonate.

• What it is: A mineral compound (MgCO3), also known as E504(i).
• What it does: Works as an anti-caking agent, acidity regulator, and carrier for colors and flavors.
• Where it’s found: Table salt, spice blends, powdered drinks, cocoa, and grated cheese.
• Appearance: Fine, white, tasteless powder.
• Dietary notes: Mineral origin; suitable for vegetarians and vegans.
• Regulation: Approved in the US as GRAS (generally recognized as safe) and authorized in the EU with defined specifications.

Why is Magnesium carbonate added to food?

Manufacturers use magnesium carbonate to keep powders from clumping, to stabilize acidity, and to help distribute small amounts of additives uniformly through a mix. In US regulation it is affirmed as GRAS (generally recognized as safe) for use as a multipurpose ingredient under good manufacturing practice, which includes its use as an anti-caking agent and neutralizing agent.¹ The European Union also lists magnesium carbonates (E504) as authorized additives and specifies their identity and purity for food use.²

What foods contain Magnesium carbonate?

You’ll most often see magnesium carbonate in dry, free-flowing products where clumping is a problem, or where tiny amounts of an additive need even spread. Typical examples include:

• Table salt and salt substitutes
• Spice and seasoning blends
• Powdered drink mixes and instant coffees
• Cocoa powder and hot chocolate mixes
• Grated or shredded hard cheeses
• Confectionery dusting sugars and baking mixes

It may also appear as a “carrier” that helps disperse colorings or flavorings throughout a product, a role noted in EU specifications for E504.²

What can replace Magnesium carbonate?

If a recipe or product needs a different anti-caking agent or carrier, common alternatives include:

• Calcium carbonate
• Tricalcium phosphate
• Silicon dioxide
• Calcium silicate
• Sodium aluminium silicate

The best substitute depends on the food type, moisture level, and labeling needs.

How is Magnesium carbonate made?

Food‑grade magnesium carbonate can be produced by reacting magnesium oxide or magnesium hydroxide with carbon dioxide, or by precipitating it from magnesium salts (such as magnesium chloride) using carbonate. EU specifications describe E504(i) as magnesium carbonate with defined purity limits and identify these typical manufacturing routes for food use.²

Is Magnesium carbonate safe to eat?

Yes—when used as intended. In the United States, magnesium carbonate is affirmed as GRAS and may be used in food at levels consistent with good manufacturing practice.¹ In the European Union, the EFSA Panel re‑evaluated magnesium carbonates (E504) and concluded there is no safety concern at reported uses and use levels in foods.³

Does Magnesium carbonate have any benefits?

Magnesium is an essential mineral that supports normal muscle and nerve function, energy metabolism, and bone health.⁴ However, magnesium carbonate is typically used at very low levels in foods to control texture or carry other ingredients, so it usually contributes only a small amount to overall magnesium intake.

Who should avoid Magnesium carbonate?

Most people don’t need to avoid magnesium carbonate in foods. That said:

• People with significant kidney disease may need to limit magnesium because the body clears magnesium through the kidneys; they should follow medical advice on total magnesium intake.⁴
• Very high intakes of readily absorbable magnesium salts (usually from supplements or medicines) can cause diarrhea; this is not typical from food additive use.⁴ EFSA’s review of E504 found no safety concern at reported uses in foods.³

Myths & facts

• Myth: “Magnesium carbonate is the same as ‘chalk’ used for climbing, so it’s not food-safe.” Fact: Food-grade magnesium carbonate must meet strict identity and purity specifications defined in EU law and is separately regulated in the US as GRAS for its intended uses.²¹
• Myth: “It dramatically changes the taste of food.” Fact: Magnesium carbonate is used at very low levels and is virtually tasteless in typical applications.
• Myth: “It’s an aluminum additive.” Fact: Magnesium carbonate contains magnesium and carbonate—no aluminum.

Magnesium carbonate in branded foods

On ingredient lists, look for “magnesium carbonate,” “E504,” or “E504(i).” It often appears on labels of table salt, spice mixes, powdered drinks, baking and dessert mixes, cocoa powders, and grated cheeses. If present as a carrier, it may be listed alongside colors or flavors it helps disperse.

References

Footnotes

1. 21 CFR §184.1425 Magnesium carbonate — U.S. FDA. https://www.ecfr.gov/current/title-21/part-184/section-184.1425 ↩ ↩² ↩³

2. Commission Regulation (EU) No 231/2012 (food additive specifications), entry for E 504 — EUR‑Lex. https://eur-lex.europa.eu/eli/reg/2012/231/2016-10-04 ↩ ↩² ↩³ ↩⁴

3. Re‑evaluation of magnesium carbonate (E 504) as a food additive — EFSA Journal. https://www.efsa.europa.eu/en/efsajournal/pub/5360 ↩ ↩²

4. Magnesium Fact Sheet for Health Professionals — NIH Office of Dietary Supplements. https://ods.od.nih.gov/factsheets/Magnesium-HealthProfessional/ ↩ ↩² ↩³