Polyphosphates

also: Sodium polyphosphate · Sodium hexametaphosphate · Potassium polyphosphate · Sodium calcium polyphosphate

Phosphate chains that make ham, prawns and processed cheese hold on to water. European reviewers found children already go over the phosphate limit on average.

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An ingredient list from the cooked and cured meats aisle

Pork (96%), salt, wheat dextrose, stabilisers (di, tri and polyphosphates), antioxidant (sodium ascorbate), preservatives (sodium nitrite, sodium nitrate).

E452

Polyphosphates

Regular intake from processed food can push total phosphate higher than is good for the kidneys.

VeganVegetarian

430

of the 43,325 UK supermarket foods we checked declare E452 in their ingredients

That is 1.0%, counted by its code or its name.

Only 21% of these labels print “E452”. Most use the name: look for “polyphosphates”.

Counted by NutraSafe from UK supermarket ingredient lists, September 2026. How we counted

How common it is in UK food, by aisle

Ready meals and pizza91 products1.9% of 4,833
Cooked and cured meats88 products4.5% of 1,938
Fresh meat, poultry and fish81 products1.7% of 4,835
Cheese42 products4% of 1,049

What polyphosphates is, what it does and where you will see it

Why it’s worth knowing. Regular intake from processed food can push total phosphate higher than is good for the kidneys. Children and people with reduced kidney function are most at risk, because their kidneys struggle to clear the extra.

What is it?

Polyphosphates are chains of phosphate units linked together, sold as sodium, potassium or calcium salts. E452 covers sodium polyphosphate (E452i), potassium polyphosphate (E452ii), sodium calcium polyphosphate (E452iii), calcium polyphosphates (E452iv) and ammonium polyphosphate (E452v). Phosphorus is a mineral the body needs, found in meat, fish, dairy and pulses. The additive form adds a concentrated, easily absorbed dose on top.

What does it do?

They bind to the protein in meat and seafood, so it holds water through processing and cooking. That keeps it juicier and helps it keep longer, partly by trapping traces of metal that make fats go rancid. In processed cheese they spread the fat and protein evenly. Because they hold water so well, they can add real weight to products such as prawns or cooked ham.

Where you will see it

Processed meat (cooked ham, bacon, sausages, chicken nuggets, reformed meat), frozen and chilled seafood (prawns, scallops, fish portions), processed and spreadable cheese, tinned fish and some bread improvers. Labels call it polyphosphates, sodium polyphosphate, potassium polyphosphate or E452.

What the science says

Kidneys and too much phosphate

The kidneys control how much phosphate stays in the blood. Additive phosphate on top of the phosphate already in food can push the total past what healthy kidneys clear comfortably, and past what damaged kidneys can clear at all. For people with chronic kidney disease, about 1 in 10 UK adults, high phosphate speeds up kidney damage and raises the risk of hardened blood vessels. European reviewers said plainly that their daily limit does not cover people with moderate to severe kidney disease.

Reviewers set a shared daily limit of 40mg of phosphorus per kg of body weight for all phosphate additives (E338 to E341, E343, E450 to E452), and said it does not apply to people with moderate to severe kidney disease.

2019Regulator reviewEFSA Panel on Food Additives and Flavourings (FAF), EFSA Journal

In people with chronic kidney disease, high phosphate intake is associated with faster loss of kidney function and more deaths from any cause, based on a large body of observational evidence reviewed by EFSA.

2019ObservationalEFSA Panel on Food Additives and Flavourings (FAF), EFSA Journal

Children already go over the limit

European reviewers found that babies, toddlers and children in Europe go over the shared phosphate limit even at average intakes. At the highest intakes, teenagers did too. Polyphosphates are in many processed foods children eat.

Intake estimates based on measured data went over the shared daily limit of 40mg per kg of body weight for babies, toddlers and children at average intakes, and for babies, toddlers, children and teenagers at the highest intakes (top 5%).

2019Regulator reviewEFSA Panel on Food Additives and Flavourings (FAF), EFSA Journal

Additive phosphate is absorbed almost completely

The phosphate in additives dissolves easily in the gut, so the body absorbs far more of it than the phosphate bound up in protein in natural food. So the phosphorus load from processed food is heavier than its share of the label suggests. Researchers have flagged this as a reason additive phosphate can add to kidney and blood vessel risk even at legal levels.

Phosphate from additives is almost completely absorbed, close to 100%, against roughly 40 to 60% from phosphate in protein-rich natural foods.

2012ObservationalRitz et al., Deutsches Arzteblatt International

Added water in prawns and ham

Polyphosphates are widely used in frozen prawns and other seafood to soak up and hold water, which adds to the weight you pay for. This is a labelling and value issue rather than a health one, but it shows how much some foods rely on this additive.

Market surveys have found polyphosphate-treated frozen prawns holding added water, measurable through their phosphorus content, which misleads shoppers on how much they are getting.

ObservationalConsumer and enforcement investigations

Where it stands with the regulators

Approved in the UK and the EU

Daily limit. 40mg of phosphorus per kg of body weight a day, shared by all phosphate additives (E338 to E341, E343, E450 to E452). Does not apply to people with moderate to severe kidney disease.

Legal basis: On the Food Standards Agency's approved list for Great Britain. The shared daily limit of 40mg per kg of body weight, measured as phosphorus, covers all phosphate additives together.
Permitted foods: Processed meat · Tinned and preserved fish and seafood · Processed cheese · Frozen coated fish and seafood · Bread (as an improver) · Drink powders · Surimi and seafood sticks
Maximum levels: Depends on the food, usually 2,000 to 5,000mg per kg, measured as phosphorus pentoxide. No set maximum in some foods.
History: Phosphate additives have been allowed in Europe for decades. European reviewers completed a full review in 2019, set a shared daily limit of 40mg per kg, raised concern that children go over it at average intakes, and said the limit does not protect people with kidney disease. The European Commission asked for more technical data in 2020 to decide whether levels in foods children eat should come down. The UK kept the EU rules after Brexit.

Who should be careful

People with chronic kidney disease or reduced kidney function should talk to their doctor or kidney dietitian about phosphate from processed food. People on a kidney diet are usually already limiting it, and polyphosphate-treated foods such as processed meat, prawns and processed cheese are often on restricted lists. Look for polyphosphates, sodium polyphosphate, potassium polyphosphate or E452.

The honest read

Polyphosphates are approved, widely used, and phosphorus is a genuine nutrient, yet the research has grown steadily more uncomfortable. The 2019 European review found children in Europe already going over the phosphate limit on average, which is unusual for a permitted additive. The concern is not one product but the total across a diet heavy in processed meat, processed cheese and treated seafood. Healthy adults with good kidneys handle normal amounts. For the roughly 1 in 10 with chronic kidney disease, high additive phosphate is a recognised clinical problem. The heart evidence in the general population is inconsistent. The kidney evidence is stronger.

Common questions about polyphosphates

Is E452 banned in the UK?

No. Polyphosphates are approved in the UK in a range of processed foods, including meat, seafood and cheese.

Should people with kidney disease avoid E452?

People with moderate to severe kidney disease are usually told by kidney dietitians to limit all phosphate, including additive phosphate from processed food. European reviewers said plainly that their daily limit does not protect people with poor kidney function.

What foods contain E452?

Mostly processed and cooked meat (ham, bacon, sausages, chicken), frozen prawns and seafood, processed and spreadable cheese, and some tinned fish. Labels call it polyphosphates, sodium polyphosphate, potassium polyphosphate or E452.

Is E452 vegan?

The salts are minerals and vegan, but E452 is mainly used in meat, seafood and processed cheese, so most foods containing it are not. Check the full ingredient list.