E343 - Magnesium phosphates

At a glance

• What it is: A family of salts—monomagnesium phosphate, dimagnesium phosphate, and trimagnesium phosphate—grouped under E343.
• What it does: Stabilises and thickens foods; can help regulate acidity and support consistent texture.
• Where you’ll see it: On EU ingredient lists as “E343” or “magnesium phosphate.”
• Related additives: Other phosphates like sodium phosphates, potassium phosphates, calcium phosphates, and phosphoric acid.
• Safety snapshot: EFSA (European Food Safety Authority) set a group Acceptable Daily Intake (ADI) for phosphates of 40 mg/kg body weight per day, expressed as phosphorus.

Why is Magnesium phosphates added to food?

E343 covers several magnesium salts of phosphoric acid—monomagnesium, dimagnesium, and trimagnesium phosphate—used for their reliable performance in food processing.¹ As part of the phosphate group, they function mainly as stabilisers and thickeners, and also help regulate acidity, support emulsification in certain foods, and maintain texture during heating and storage.²

What foods contain Magnesium phosphates?

In the EU, magnesium phosphates are authorised in a range of food categories under the broader “phosphates” group, with conditions and limits set in law.³ If present, they appear in the ingredient list as “E343” or “magnesium phosphate”; some labels may specify the particular form (mono-, di-, or tri-magnesium phosphate).

What can replace Magnesium phosphates?

Depending on the job they do in a recipe, possible substitutes include:

• Other phosphates for similar functionality: sodium phosphates, potassium phosphates, calcium phosphates, diphosphates, triphosphates, or polyphosphates.
• Non-phosphate acid regulators and buffers when pH control is the main need: citric acid or sodium citrates.
• Mineral fillers or firmness agents in some applications: calcium carbonates.

The best substitute depends on the food type and the specific function (thickening, stabilising, or pH control).

How is Magnesium phosphates made?

Food-grade magnesium phosphates are typically produced by neutralising purified phosphoric acid with magnesium oxide, magnesium hydroxide, or magnesium carbonate, followed by controlled crystallisation and drying to yield the mono-, di-, or tri-magnesium salts.¹

Is Magnesium phosphates safe to eat?

EFSA re-evaluated the safety of phosphates (including E343) and established a group ADI of 40 mg/kg body weight per day, expressed as phosphorus.² Within that framework, EFSA did not identify concerns for genotoxicity or carcinogenicity when phosphates are used as authorised in foods.² As with all additives, actual use levels and permitted food categories are regulated in the EU.³

Does Magnesium phosphates have any benefits?

From a food-technology perspective, E343 helps keep products stable and uniform, reduces texture changes during heating or storage, and can assist with acidity control. In cheese-style applications, phosphates are valued for improving melt and texture, which is why the group is widely used in processed cheese technology.²

Who should avoid Magnesium phosphates?

• People advised to limit phosphate intake (for example, individuals with chronic kidney disease) should monitor total dietary phosphorus from both foods and additives, in consultation with their healthcare provider.²
• Those sensitive to supplemental magnesium should be aware that high intakes of magnesium from supplements and medicines can cause gastrointestinal upset (such as diarrhoea), and excess magnesium can be risky in people with impaired kidney function.⁴ Typical amounts of E343 used as a food additive are much lower than supplemental doses.

Myths & facts

• Myth: “All phosphates are the same.” Fact: Phosphates include many different salts (sodium, potassium, calcium, magnesium, and different chain lengths), each with distinct properties in food.
• Myth: “Phosphates only add ‘chemicals’ without purpose.” Fact: They perform clear roles such as stabilising texture, controlling acidity, and improving processing reliability.
• Myth: “If a product lists E343, it must be high in phosphorus.” Fact: The ingredient list shows presence, not amount. Regulations control how much can be used.

Magnesium phosphates in branded foods

On labels, look for “E343,” “magnesium phosphate,” or a specific form such as “monomagnesium phosphate,” “dimagnesium phosphate,” or “trimagnesium phosphate.” Ingredient lists order items by weight, so position on the list gives a rough sense of relative amount, not an exact quantity.

References

Footnotes

1. Commission Regulation (EU) No 231/2012 — Specifications for food additives. https://eur-lex.europa.eu/eli/reg/2012/231/oj ↩ ↩²

2. Re-evaluation of phosphates (E 338–341, E 343, E 450–452) as food additives — EFSA Journal. https://www.efsa.europa.eu/en/efsajournal/pub/5674 ↩ ↩² ↩³ ↩⁴ ↩⁵

3. Regulation (EC) No 1333/2008 on food additives — Authorisation and conditions of use. https://eur-lex.europa.eu/eli/reg/2008/1333/oj ↩ ↩²

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