E338 – Phosphoric Acid - Food additives database

Safety grading ORANGE – SOME CONCERNS

Phosphoric acid (E338) is graded ORANGE because, while legally permitted in both the EU and US, its excessive consumption is linked to health concerns. It is widely used as an acidity regulator in soft drinks and processed foods. Scientific reviews highlight that frequent intake may contribute to dental erosion, reduced bone mineral density, and possible kidney issues. Cola beverages, in particular, are the largest dietary source of phosphoric acid for many people. The acid itself is not carcinogenic or toxic in small amounts, but its role in dietary imbalances and potential metabolic effects has been criticized.

Regulatory bodies such as EFSA and FDA consider it safe within established limits (acceptable daily intake “not specified”), meaning it is considered low-risk when used as intended. However, public health concerns arise from overconsumption in drinks, which can replace healthier options like milk and water. Several epidemiological studies associate high intake of phosphoric acid containing sodas with increased risks of osteoporosis, dental caries, and kidney stones. These associations justify an ORANGE classification: the additive itself is legal and not directly harmful in regulated amounts, but its widespread use raises justified health concerns when consumed excessively.

Should You Avoid E338?

Moderate consumption is considered safe. If you drink sodas occasionally, phosphoric acid will not harm you directly. However, frequent or daily consumption may increase your risks of dental problems and bone density reduction, particularly in women. Individuals with kidney disease or those prone to kidney stones should be especially cautious. Choosing water, mineral water, or juices without phosphoric acid is a healthier alternative.

Common Uses

Cola and dark-colored sodas (main source worldwide)
Processed meats (as acidity regulator)
Dairy products and cheese spreads (texture adjustment)
Baked goods (dough conditioner)
Jams and preserves (pH control)
Industrial applications (not food, but in cleaning products and rust removal)

Common Names / Synonyms

Phosphoric(V) acid
Orthophosphoric acid
O-Phosphoric acid
Phosphate acid

What is it?

Phosphoric acid is an inorganic mineral acid with the chemical formula H₃PO₄. In food production, it is used primarily as an acidity regulator, giving a sharp tang to cola drinks and stabilizing pH in many processed foods. Commercially, it is produced by two main methods: the thermal process and the wet process. The thermal process involves burning elemental phosphorus to form phosphorus pentoxide, which is then hydrated to yield phosphoric acid. This route produces a very pure form of the acid, typically reserved for food and pharmaceutical applications. The wet process, more common industrially, involves treating phosphate rock with sulfuric acid, generating phosphoric acid along with gypsum byproducts. Food-grade phosphoric acid is purified to remove heavy metals and contaminants.

As a compound, it is colorless, odorless, and moderately strong as an acid, though less corrosive than hydrochloric or sulfuric acid. In beverages, it imparts the distinct “bite” associated with colas, balancing sweetness and acting as a preservative. Because of its role in human metabolism phosphates are vital for bones, teeth, and energy transfer, phosphoric acid is generally considered biocompatible. Still, concerns arise when intake is unbalanced, especially if high phosphoric acid intake coincides with low calcium intake. Long-term dietary imbalance may contribute to health risks, which is why its heavy use in soft drinks continues to be debated.

Where it’s allowed (EU vs US)

E338 is approved in both the European Union and the United States. The EU allows its use in a wide variety of foodstuffs as an acidity regulator. In the US, the FDA lists it as “Generally Recognized as Safe” (GRAS) when used in accordance with good manufacturing practice. Both regions regulate maximum levels depending on the food category.

E338 – Phosphoric Acid