E339II - Disodium phosphate

At a glance

• What it is: A white, water‑soluble salt also called disodium hydrogen phosphate or secondary sodium phosphate.
• What it does: Controls acidity (pH), acts as an emulsifying salt, stabiliser, sequestrant (binds minerals), and humectant (helps retain moisture).
• Where you find it: Processed cheeses, some dairy drinks and creamers, baked goods, instant mixes, and ready meals.
• Dietary notes: Provides phosphorus and sodium; excessive phosphate intake can matter for some people with kidney or heart conditions.
• Regulatory status: Authorised in the EU as E339ii with purity specifications; evaluated with a group Acceptable Daily Intake (ADI) for phosphates by EFSA, the European Food Safety Authority.¹²

Why is Disodium phosphate added to food?

Manufacturers use disodium phosphate to keep food at a steady acidity, which protects taste and texture over shelf life. As an “emulsifying salt” in processed cheese, it binds calcium and helps the cheese melt smoothly without oiling off.³ It also works as a sequestrant (it ties up metal ions that can cause off‑flavors or texture problems), a stabiliser to help products hold together, and a humectant to help foods stay moist.

What foods contain Disodium phosphate?

You’re most likely to see it in:

• Processed and spreadable cheeses, where it is a standard emulsifying salt.³
• Dairy and dairy‑style products such as evaporated milk, creamers, and some yogurt or dessert mixes.
• Instant puddings, powdered beverages, and hot cocoa mixes.
• Baked goods and mixes, where it helps control pH and works with leavening.
• Ready meals, soups, and sauces that need stable texture during heating and storage.

On ingredient lists, it may appear as “disodium phosphate,” “disodium hydrogen phosphate,” “sodium phosphate (dibasic),” or “E339(ii).”

What can replace Disodium phosphate?

Possible substitutes depend on the job it performs:

• For cheese emulsification: sodium citrate or trisodium phosphate can play similar roles in some recipes.³
• For acidity and buffering: citric acid, phosphoric acid, or monosodium phosphate may be used.
• For mineral binding or stabilising: other phosphate salts such as diphosphates, triphosphates, or polyphosphates; or non‑phosphate options like sodium bicarbonate with citric acid in leavening systems.
• For sodium reduction: potassium alternatives such as potassium phosphates are sometimes chosen.

How is Disodium phosphate made?

Food‑grade disodium phosphate is typically produced by neutralising food‑grade phosphoric acid with sodium hydroxide or sodium carbonate, followed by crystallisation and drying to meet purity specifications.² It is sold as anhydrous or hydrated crystals; all forms dissolve readily in water and have a mildly alkaline reaction.⁴

Is Disodium phosphate safe to eat?

In the European Union, EFSA (the European Food Safety Authority) re‑evaluated phosphoric acid and phosphate salts (E 338–341, E 343, E 450–452) and set a group ADI (Acceptable Daily Intake) of 40 mg phosphorus per kg body weight per day for total phosphate additives from all sources.¹ This opinion supports their continued use within regulated limits. U.S. regulations also allow disodium phosphate in certain foods; for example, it is an approved emulsifying salt in pasteurised process cheese.³

Does Disodium phosphate have any benefits?

• Food quality: Helps cheese melt smoothly, keeps sauces from separating, and maintains a stable pH during cooking and storage.³
• Process tolerance: Improves heat stability in dairy products, reducing curdling.
• Nutrition note: It contributes phosphorus, an essential mineral, though phosphate additives are used for function rather than as a nutrient source.

Who should avoid Disodium phosphate?

• People with chronic kidney disease (CKD) or those advised to limit phosphorus should be cautious with phosphate additives, including disodium phosphate.¹
• EFSA noted that children with high intake of phosphate additives could exceed the group ADI, so frequent consumers of many processed foods may want to watch total exposure.¹
• Individuals on low‑sodium diets may also wish to monitor products that contain multiple sodium salts.

If you have a medical condition, ask your healthcare professional about your personal limits.

Myths & facts

• “All phosphates are the same.” Fact: Different phosphate salts (mono‑, di‑, tri‑ and polyphosphates) behave differently in food and are not interchangeable.
• “It’s only a preservative.” Fact: Its main roles are pH control, emulsifying, sequestration, and stabilisation; it is not primarily used to kill microbes.
• “Industrial equals unsafe.” Fact: Food‑grade disodium phosphate must meet strict purity standards set in law before it can be used in foods.²
• “It makes any cheese melt.” Fact: It works in processed cheese systems designed for emulsifying salts, not in natural cheeses without processing aids.³

Disodium phosphate in branded foods

You’ll often spot it on labels for:

• Processed cheese slices, cheese spreads, and cheese sauces.
• Powdered creamers, cocoa mixes, and instant puddings.
• Ready‑to‑heat soups, sauces, and side dishes. On packaging, look for “disodium phosphate,” “sodium phosphate (dibasic),” or “E339(ii).”

References

Footnotes

1. Re-evaluation of phosphoric acid–phosphates–di-, tri- and polyphosphates (E 338–341, E 343, E 450–452) as food additives — EFSA Journal (2019). https://www.efsa.europa.eu/en/efsajournal/pub/5674 ↩ ↩² ↩³ ↩⁴

2. 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/eli/reg/2012/231/oj ↩ ↩² ↩³

3. Pasteurized Process Cheese — U.S. FDA, 21 CFR §133.169. https://www.ecfr.gov/current/title-21/chapter-I/subchapter-B/part-133/subpart-B/section-133.169 ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶

4. Disodium phosphate — PubChem, National Library of Medicine (NIH). https://pubchem.ncbi.nlm.nih.gov/compound/Disodium-phosphate ↩