Is Phosphoric Acid (E338) Vegan?

Also known as: Orthophosphoric acid, Phosphoric(V) acid, H3PO4

Vegan

Phosphoric acid is vegan. Producers make it from mined phosphate rock treated with sulfuric acid, then purify it to food grade. The bone-derived phosphate that people confuse it with is a different additive, E542.

Last checked How we decide

Ingredient Data

Vegan Status

Vegan

E-Number

E338

Also Known As

Orthophosphoric acid; Phosphoric(V) acid; H3PO4

Source

Refined from mined phosphate rock. The wet process digests the ore in sulfuric acid and purifies the resulting acid to food grade by solvent extraction. The thermal process burns elemental phosphorus and hydrates the oxide, giving a purer acid at higher energy cost. Both start from sedimentary rock.

Commonly Found In

Cola and other soft drinks, some beers, jams, processed cheese, baking powder, cured meats, sports drinks, and dental products. Also used industrially as a rust converter and in fertilizer manufacture.

Vegan Alternative

No substitute needed. E338 is vegan.

Additional Notes

Phosphoric acid is what gives cola its sharp bite and much of its low pH, sitting around 2.5 in a finished drink. Regular high intake of phosphate additives has been studied in relation to bone density and kidney function, and EFSA set a group acceptable daily intake for phosphates in 2019. Bone-derived phosphate is a separate additive numbered E542.

In depth

Rock, Acid, and a Long-Dead Bone Route

Phosphate rock is mined in Morocco, China, the United States, Russia, and Jordan, laid down as marine sediment over geological time. The wet process grinds the ore and digests it in sulfuric acid, producing phosphoric acid and a gypsum byproduct. Food-grade acid is then purified by solvent extraction to strip out fluoride, heavy metals, and organic matter. The thermal process takes a different path, reducing phosphate rock in an electric furnace to elemental phosphorus, burning that to phosphorus pentoxide, and hydrating it.

The product is purer and the energy cost is higher. History explains why people ask about bones. Hennig Brand isolated phosphorus from urine in 1669, and eighteenth and nineteenth century producers moved to bone ash, which is rich in calcium phosphate. Mineral rock replaced bone as industry scaled up. Modern food-grade phosphoric acid is made from ore, and the one phosphate additive still made from bone carries its own number, E542.

Cola and the Bone Density Question

Phosphoric acid gives cola its tang and holds the pH near 2.5. The low pH also helps preserve the drink. Citric acid does a similar job in lemon and orange sodas. The two acids taste distinctly different, which is part of why cola tastes like cola. Observational studies have linked heavy cola consumption to lower bone mineral density, particularly in women. Whether phosphoric acid causes that, or whether cola simply displaces milk and other calcium sources in the diet, remains debated.

Studies on other carbonated drinks without phosphoric acid have generally not shown the same association. EFSA re-evaluated phosphates in 2019 and set a group acceptable daily intake of 40 mg per kilogram of body weight per day as phosphorus, noting that some high consumers exceed it. People with reduced kidney function are commonly advised to limit added phosphates, since additive phosphorus is absorbed far more readily than the phosphorus in whole foods.

The Phosphate Range on Labels

Phosphoric acid heads a long range of related additives: E339 sodium phosphates, E340 potassium phosphates, E341 calcium phosphates, E343 magnesium phosphates, E450 diphosphates, E451 triphosphates, and E452 polyphosphates. All are made from the same mineral acid neutralized with different bases. One number breaks the pattern. E542, bone phosphate, is made from degreased animal bones and is not vegan. Learning that single exception makes the rest of the range readable at a glance. Phosphates cluster in processed meat, seafood, and cheese. The E-number often appears in products that are not vegan for other reasons. The additive stays mineral in every one of them.

Frequently asked questions

Is E338 vegan?

Yes. Phosphoric acid is made from mined phosphate rock digested in sulfuric acid, then purified to food grade. No animal-derived material is used in commercial production.

Does phosphoric acid come from bones?

Not today. Bone ash was a production route in the eighteenth and nineteenth centuries, replaced by mineral rock as industry scaled. Bone-derived phosphate survives as a separate additive, E542, which is not vegan.

Is the phosphoric acid in cola bad for bones?

The evidence is mixed. Observational studies link heavy cola drinking to lower bone density. Other carbonated drinks without phosphoric acid have not shown the same pattern, so displacement of calcium-rich drinks may explain part of it.

Which phosphate additives are not vegan?

Only E542, bone phosphate, which is made from degreased animal bones. Every other phosphate in the E338 to E452 range comes from mined phosphate rock. All of them are mineral in origin.

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