E339 - Sodium phosphates

At a glance

• What it is: a family of salts of phosphoric acid used for buffering, emulsifying, thickening, and moisture retention.
• Common forms: monosodium phosphate (E339(i)), disodium phosphate (E339(ii)), and trisodium phosphate (E339(iii)).
• Where you’ll see it: processed cheese, processed meats, baked goods, dairy-based sauces, and powdered mixes.
• Why it’s used: to stabilize pH, bind water, improve texture, and support leavening.
• Safety: evaluated by EU and U.S. authorities; an Acceptable Daily Intake (ADI) applies in the EU for total phosphate additives. See details below.

Why is Sodium phosphates added to food?

Food makers use sodium phosphates because they solve several practical problems at once:

• Buffering and pH control: they keep acidity in a stable, helpful range, which protects flavor and texture.
• Emulsifying: they help fat and water stay mixed, which is vital in processed cheese and creamy sauces.
• Water binding: they hold moisture in meats and seafood, improving juiciness and yield during cooking.
• Sequestration: by tying up trace metals, they slow oxidation that can cause off-flavors.
• Leavening support: they can work with alkaline leaveners like sodium bicarbonate to control gas release in baked goods.
• Process efficiency: consistent pH and texture make manufacturing more reliable.

What foods contain Sodium phosphates?

You’re most likely to find E339 in:

• Processed and spreadable cheeses, and cheese sauces (used as “emulsifying salts” to ensure smooth melt and stable texture). U.S. standards for pasteurized process cheese list sodium phosphate among permitted emulsifying salts.¹
• Processed meats and poultry products, where it helps retain moisture and tenderness.
• Baked goods and mixes, often alongside sodium carbonates and related phosphate leavening acids.
• Dairy products and creamers, where it helps manage acidity and protein stability.
• Powdered drinks, instant puddings, and other mixes for pH control and dispersion.

On labels, look for “monosodium phosphate,” “disodium phosphate,” or “trisodium phosphate,” or the E-number “E339.”

What can replace Sodium phosphates?

Depending on the job, formulators may use:

• Other emulsifying salts and buffers: sodium citrates.
• Other phosphates: diphosphates, triphosphates, or polyphosphates.
• Acidulants and buffers for pH: citric acid.
• Alternate leavening systems: combinations of sodium bicarbonate with suitable acid salts.

The best substitute depends on whether you need pH control, emulsification, moisture binding, or leavening.

How is Sodium phosphates made?

Commercial sodium phosphates are produced by neutralizing food-grade phosphoric acid with alkaline sodium sources such as sodium hydroxide, sodium carbonates, or sodium bicarbonate, then drying and milling to specification.²

Is Sodium phosphates safe to eat?

• European Union: EFSA (European Food Safety Authority) re-evaluated phosphates used as additives (E 338–341, E 343, E 450–452) and set a group Acceptable Daily Intake (ADI) of 40 mg/kg body weight per day, expressed as phosphorus, from all phosphate additives combined.³ This ADI is intended to cover typical uses across many foods.
• United States: Sodium phosphate salts are listed by FDA as permitted food additives/ingredients and are used in line with Good Manufacturing Practice (GMP), meaning only as much as needed for the intended technical effect.⁴

As with many additives, overall exposure depends on how much processed food you eat that contains phosphate additives.

Does Sodium phosphates have any benefits?

• Functional: It improves texture, melt, and stability in foods like processed cheese and keeps meats juicier by binding water.
• Nutritional context: Phosphorus is an essential mineral involved in bone health and energy metabolism; however, most people get enough from ordinary foods, and total intake (from both natural foods and additives) should stay within healthy ranges.⁵

Who should avoid Sodium phosphates?

• People with chronic kidney disease (CKD) or those advised to follow a low-phosphorus diet should limit phosphate additives, because reduced kidney function makes it harder to manage blood phosphorus levels.⁶
• Anyone told by a healthcare professional to restrict phosphorus should read labels for phosphate ingredients (including E339 and related phosphates).

Myths & facts

• Myth: “All phosphates in food are harmful.”
  Fact: Phosphates are widely used and regulated. Safety evaluations consider typical dietary exposure, and authorities set limits where needed.³
• Myth: “E339 is only a preservative.”
  Fact: Sodium phosphates mainly act as pH buffers, emulsifiers, and moisture binders; preservation is not their primary role.
• Myth: “If a food has E339, it must be ultra-processed.”
  Fact: E-numbers indicate an approved additive in the EU. They don’t, by themselves, define how processed a food is.

Sodium phosphates in branded foods

• How it appears on labels: monosodium phosphate, disodium phosphate, trisodium phosphate, or E339.
• Where to spot it: ingredient lists of processed cheeses, meat and poultry products, baking mixes, cheese sauces, creamers, and powdered beverages.
• Shopping tip: If you’re managing phosphorus intake, compare similar products—some use sodium citrates or lower overall phosphate levels.

References

Footnotes

1. Pasteurized process cheese (21 CFR 133.169) — eCFR, U.S. GPO. https://www.ecfr.gov/current/title-21/part-133/section-133.169 ↩

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

3. Re-evaluation of phosphoric acid–phosphates–di-, tri- and polyphosphates (E 338–341, E 343, E 450–452) as food additives — EFSA Journal (2019) 17(6):5674. https://efsa.onlinelibrary.wiley.com/doi/10.2903/j.efsa.2019.5674 ↩ ↩²

4. Food Additive Status List — U.S. FDA. https://www.fda.gov/food/food-additives-petitions/food-additive-status-list ↩

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

6. Phosphorus and Chronic Kidney Disease — NIDDK, NIH. https://www.niddk.nih.gov/health-information/kidney-disease/ckd/food-choices-phosphorus-kidney-disease ↩