E-numbers / Other additives / E340
also: Monopotassium phosphate · Dipotassium phosphate · Tripotassium phosphate · Potassium orthophosphate
Phosphate salts that stop processed cheese splitting and keep creamers smooth. They add to the phosphorus you eat, which matters most for people with kidney disease.
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Oat Base (Water, Oats 14%), Rapeseed Oil, Calcium Carbonate, Acidity Regulator (Dipotassium Phosphate), Salt, Vitamins (B2, D, B12), Potassium Iodide
Added phosphates raise how much phosphorus you take in.
277
of the 43,325 UK supermarket foods we checked declare E340 in their ingredients
That is 0.6%, counted by its code or its name.
Counted by NutraSafe from UK supermarket ingredient lists, September 2026. How we counted
Why it’s worth knowing. Added phosphates raise how much phosphorus you take in. High phosphorus intake is linked to worse kidney function over time, and people with kidney disease cannot clear it well. Regular high intake may also upset the balance of calcium in bones.
Potassium phosphates are made by combining phosphoric acid with a potassium mineral. There are three forms: monopotassium phosphate (E340a), dipotassium phosphate (E340b) and tripotassium phosphate (E340c). All are white powders that dissolve in water.
They keep a food at a steady level of acidity. They also stop fat and water separating in processed cheese and coffee creamers, trap traces of metal that would make fats go rancid, help meat hold water, and help cakes rise. In drinks they soften sharpness and improve texture.
Processed cheese and cheese slices, UHT cream, flavoured milk drinks, instant coffee, powdered creamers, cured and reformed meat, seafood sticks, bread and cake mixes, and sports and protein drinks. UK labels call it potassium phosphates, dipotassium phosphate or E340.
The body absorbs the phosphate added to processed food more easily than the phosphorus that occurs naturally in whole foods. The kidneys have to filter out the extra. In people with chronic kidney disease they cannot keep up, so phosphate builds up in the blood, which is linked to heart problems and faster decline. Even in healthy adults, a steady high intake adds to the kidneys' workload over time.
European 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 this limit does not protect people with moderate to severe kidney disease.
The body absorbs about 80 to 100% of the phosphate from additives, against about 40 to 60% of the phosphorus in whole foods. So added phosphate raises blood phosphate more for each milligram eaten.
High blood phosphate was linked to more deaths from heart disease in people with kidney disease, and in the general population in some long-term studies.
The NutriNet-Santé study asked more than 100,000 French adults to record everything they ate, then followed their health for about 7 years. People who ate more potassium phosphates were more likely to develop type 2 diabetes. This shows a link, not proof that E340 causes diabetes, and the researchers called for more research.
Among 104,139 French adults followed for an average of 6.8 years, each extra 500mg of potassium phosphates eaten a day was linked to a 15% higher risk of type 2 diabetes.
Phosphorus and calcium work as a pair in the body. Eating a lot of phosphorus compared with calcium, year after year, can push up the hormone that controls calcium and cut how much calcium is absorbed, which may affect bone strength over a long time. In healthy adults on a varied diet the effect is thought to be small, but it shows up in studies of large groups.
European reviewers noted that the balance of calcium and phosphorus matters for bones, and that too much phosphate compared with calcium can harm bone density.
In a trial where people ate more phosphorus with the same calcium, the hormone that controls calcium rose and signs of new bone forming fell, pointing to a harmful effect on bone.
Added phosphates are concentrated in ultra-processed food. People who eat a lot of processed meat, instant products and processed cheese can take in several times more phosphorus than whole foods alone would give them. UK labels do not show phosphorus, so there is no easy way to track how much you are getting.
Studies of Western diets estimate that additives may supply 10 to 50% of daily phosphorus in people who eat a lot of processed food.
Daily limit. 40mg of phosphorus per kg of body weight a day, shared by all phosphate additives (European reviewers, 2019). Does not apply to people with moderate to severe kidney disease.
People with chronic kidney disease or reduced kidney function should cut down on foods with added phosphates, because their kidneys cannot clear the extra phosphorus. Look for potassium phosphate, dipotassium phosphate, tripotassium phosphate or E340. People concerned about bone strength or calcium should also know that a regularly high phosphate intake works against calcium.
The concern with E340 is not one food but the total across a diet. Someone who eats processed cheese, cured meat, flavoured drinks and instant meals every day takes in a lot of added phosphorus, and the 2019 European review found the heaviest eaters could go over the daily limit. The harm is real and well recorded for people with kidney disease. In the general population the signal is there in long-term studies, but it is hard to separate from everything else in a processed diet. Where harm starts for a healthy adult is not settled. How it works is well understood.
No. Potassium phosphates are approved in the UK and EU and are on the Food Standards Agency's list.
Yes. The 2019 European review said the daily limit for phosphate additives does not protect people with moderate to severe kidney disease, and kidney specialists commonly advise cutting processed-food phosphate. Look for E340, potassium phosphate or dipotassium phosphate.
Processed cheese slices, powdered creamers, UHT cream, instant coffee, protein and sports drinks, cured and reformed meat, flavoured milk drinks, and some bread and cake mixes.
Yes. Potassium phosphates are made from minerals, with nothing from animals.
Last reviewed: 20 June 2026
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