E553A - synthetic magnesium silicates

At a glance

• What it is: A synthetic, mineral powder of magnesium and silicon oxides made to food‑grade specifications.
• What it does: Helps powders flow, prevents caking and sticking, and can act as a carrier for flavors or colors.
• Where it’s found: Dry mixes, powdered seasonings, instant beverages, tableted supplements, and chewing gum coatings.
• Regulatory status: Authorised in the EU with specific purity specifications and permitted uses in foods.¹²

Why is synthetic magnesium silicates added to food?

Food makers add E553a to keep dry products from clumping and to help powders pour smoothly. Its porous structure absorbs trace moisture and oils, which reduces stickiness and improves handling on manufacturing lines and in home kitchens. It can also serve as an inert carrier to spread tiny amounts of flavors or colors evenly through a mix.³

What foods contain synthetic magnesium silicates?

You’ll most often see E553a on labels for:

• Powdered seasonings and spice blends
• Instant drink mixes and protein powders
• Powdered sugar and bakery mixes
• Tableted or powdered dietary supplements
• Chewing gum coatings and other confections

Label names may include “magnesium silicate,” “synthetic magnesium silicate,” or “E553a.”

What can replace synthetic magnesium silicates?

Depending on the recipe and processing needs, common stand‑ins include:

• Silicon dioxide
• Talc (magnesium silicate, natural)
• Tricalcium phosphate
• Calcium carbonates
• Microcrystalline cellulose or powdered cellulose
• In some salts: sodium ferrocyanide or potassium ferrocyanide

The best substitute depends on taste neutrality, particle size, and whether the food is dry, oily, or hygroscopic (absorbs moisture).

How is synthetic magnesium silicates made?

Food‑grade E553a is typically produced by precipitating magnesium silicate from water by reacting a soluble silicate (such as sodium silicate) with a magnesium salt (such as magnesium sulfate or magnesium chloride). The solid is then filtered, thoroughly washed to remove residual salts, and dried. The result is a fine, amorphous, water‑insoluble powder with high surface area that functions as an effective anti‑caking agent.¹³

Is synthetic magnesium silicates safe to eat?

In the European Union, magnesium silicate (E553a) is an authorised food additive. The law sets detailed identity and purity criteria—covering composition and contaminant limits—to ensure it meets food‑grade quality when used in foods.¹ EU legislation also lists where food additives like E553a may be used and under what conditions.² Internationally, the Codex General Standard for Food Additives includes magnesium silicate (INS 553(i)) among anti‑caking agents permitted in foods under good manufacturing practice.³

Chemically, synthetic magnesium silicates are insoluble in water and are not expected to dissolve into available magnesium under normal digestive conditions, which supports their use as inert processing aids at permitted levels.⁴

Does synthetic magnesium silicates have any benefits?

For consumers, the benefits are practical rather than nutritional:

• Keeps powders free‑flowing and easy to measure
• Helps avoid clumps in seasonings and mixes
• Improves consistency, so each serving is similar

It does not add taste or meaningful nutrients.

Who should avoid synthetic magnesium silicates?

• People following personal or medical guidance to limit certain food additives may choose to avoid products listing E553a.
• If you are sensitive to dusts, avoid inhaling powder during bulk handling at home (for example, when refilling spice shakers). This is a general handling tip, not specific to ingestion.

Allergies to magnesium silicates are uncommon, and the additive is considered technologically necessary and safe when used as authorised.²

Myths & facts

• “It’s the same as talc.” Not exactly. Both are magnesium silicates, but E553a refers to synthetic magnesium silicate, while E553b is talc, a naturally occurring mineral. They have separate food‑grade specifications and authorisations in the EU.¹
• “It provides magnesium like a supplement.” No. E553a is water‑insoluble and is not a bioavailable source of dietary magnesium.⁴
• “It’s unregulated.” False. E553a has legally binding identity and purity criteria in the EU, and its use is governed by food additive laws.¹²

synthetic magnesium silicates in branded foods

You may find E553a on ingredient lists for powdered drink mixes, spice blends, instant soups, confectionery coatings, and some tablet‑style supplements. On packaging, it may appear as “magnesium silicate,” “synthetic magnesium silicate,” or “E553a,” often near the end of the ingredient list because it is used in small amounts.

References

Footnotes

1. Commission Regulation (EU) No 231/2012 laying down specifications for food additives listed in Annexes II and III to Regulation (EC) No 1333/2008 — EUR-Lex. https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:32012R0231 ↩ ↩² ↩³ ↩⁴ ↩⁵

2. Regulation (EC) No 1333/2008 on food additives — EUR-Lex. https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:32008R1333 ↩ ↩² ↩³ ↩⁴

3. General Standard for Food Additives (CXS 192-1995), functional classes and GMP use — Codex Alimentarius (FAO/WHO). https://www.fao.org/gsfaonline/docs/CXS_192e.pdf ↩ ↩² ↩³

4. Magnesium silicate compound summary — NIH PubChem. https://pubchem.ncbi.nlm.nih.gov/compound/Magnesium-silicate ↩ ↩²