Safety grading GREEN – SAFE
E331 refers to sodium and potassium citrates, the salts of citric acid used widely as acidity regulators, emulsifying salts and chelating agents. This group includes three sodium citrate forms: E331(i) monosodium citrate, E331(ii) disodium citrate and E331(iii) trisodium citrate, as well as potassium citrate used in similar roles. EFSA and FDA consider all citrate salts safe for their intended uses and assign them the regulatory status “ADI not specified,” a category reserved for additives with very low toxicological concern. These substances participate in normal energy metabolism via the Krebs cycle, making them physiologically familiar to the body.
The toxicological evidence shows no carcinogenic, genotoxic or reproductive concerns at realistic dietary intakes. Human exposure levels are far below doses tested in safety studies, which commonly demonstrate excellent tolerance. Sodium and potassium citrates do not accumulate in tissues and are readily metabolised. Independent reviews of citrate metabolism highlight a strong safety record, low toxicity and rapid clearance. Adverse effects occur only at very high supplemental doses, with symptoms such as mild digestive upset or electrolyte imbalance, which are not relevant to normal food consumption.
Some nutritional considerations apply to specific populations. Individuals on low-sodium diets may prefer potassium citrate forms, while individuals with impaired kidney function may need to monitor potassium intake, although typical food-level exposures are small. For the general population, E331 poses no health risk at permitted levels, and regulatory consensus is strong. Given decades of safe use and alignment of independent scientific literature, E331 receives the rating GREEN – SAFE.
Should you avoid E331?
There is no reason for most consumers to avoid E331. Citrates are among the least controversial additives and are used for essential technological functions such as pH regulation, flavour balancing and stabilisation. They contribute minimally to total sodium intake compared with table salt and processed foods. People following medical dietary guidelines may need to consider total sodium or potassium loads but not because of intrinsic toxicity of the additive.
No credible evidence links E331 with cancer, hyperactivity, allergies or long-term adverse health outcomes. The additive is well tolerated, even by sensitive individuals, and exposure is usually low. For nearly all consumers, E331 represents a low-risk additive with a clear technological role in food quality and stability.
Common uses
- Acidity regulation in soft drinks, flavoured waters and fruit beverages.
- Cheese processing, where sodium citrate acts as an emulsifying salt improving melt behaviour.
- Powdered drink mixes, instant beverages and electrolyte drinks.
- Confectionery, jellies, jams and desserts for pH control and improved flavour.
- Stabilisation of vitamins and prevention of metal-catalysed oxidation in beverages.
- Pharmaceutical syrups, effervescent formulations and oral rehydration solutions.
- Preservation of colour and freshness in canned and dehydrated foods.
Common names / Synonyms
- Monosodium citrate (E331(i))
- Disodium citrate (E331(ii))
- Trisodium citrate (E331(iii))
- Potassium citrate
- Citrate salts
- Sodium salt of citric acid
What is it?
E331 additives are the sodium or potassium salts of citric acid, an organic acid naturally present in citrus fruits and produced industrially via fermentation. Neutralising citric acid with sodium carbonate, sodium hydroxide or potassium hydroxide yields the different citrate forms. Monosodium citrate has one neutralised carboxyl group, disodium citrate has two, and trisodium citrate has all three. These differences influence their pH effect and sodium content but not their essential technological functions.
Citrates have high water solubility and excellent buffering capacity, making them effective at maintaining stable pH in foods. Their ability to bind metal ions such as calcium and iron allows them to prevent oxidation and improve product stability. In cheese production, trisodium citrate disperses casein proteins, enabling smooth melting. In beverages, citrates enhance the clarity of flavours and stabilise vitamins and colours. Their benign chemistry and close relationship to natural metabolic pathways contribute to a strong safety profile.
Citrate salts are metabolised through the Krebs cycle, yielding carbon dioxide and water. The body handles them efficiently, and they do not accumulate. This metabolic familiarity underlies the low toxicological concern recognised by regulators. The various subtypes differ mostly in their sodium or potassium content, which affects dietary considerations rather than their inherent safety.
Where it’s allowed (EU vs US)
E331 is authorised in the EU under Regulation (EC) No 1333/2008 for use in many food categories at quantum satis levels. Sodium and potassium citrates are GRAS in the United States and widely used in foods, pharmaceuticals and beverages. Other regions, including Canada, Australia and New Zealand, also approve E331 for broad applications.