Phosphoric Acid

What is acidity regulator 338?

Acidity regulator 338 is phosphoric acid, listed as E338 in the EU and as 338 in Australia and New Zealand. It is a mineral acid made from phosphate rock. In food it lowers pH, which sharpens flavor, helps preserve the product and keeps ingredients stable.

It is best known as the source of the tangy bite in colas. Coca-Cola, Pepsi and most other colas list it on the label; most lemon-lime and fruit sodas use citric acid instead. Smaller amounts appear in some processed cheeses, jams and leavening agents.

Is phosphoric acid safe?

Regulators allow it. The European Food Safety Authority re-evaluated phosphoric acid and phosphate additives in 2019 and set a group acceptable daily intake of 40mg of phosphorus per kg of body weight per day, covering all phosphate sources. In the US it is generally recognized as safe.

The concerns are about how much people consume, not about small amounts. Phosphate additives are absorbed more efficiently than the phosphorus naturally present in foods such as meat, dairy and beans, so a diet heavy in processed foods and colas can push total phosphorus intake high.

Phosphoric acid, cola and bone health

In the Framingham Osteoporosis Study, women who drank cola regularly had lower hip bone mineral density than women who drank less, while other carbonated drinks showed no such link. Researchers suggested phosphoric acid and caffeine may play a role, along with cola replacing milk in the diet.

Observational studies like this cannot prove cause and effect, and the association was not seen in men. Still, a daily cola habit is a reasonable thing to cut back if you are concerned about bone health.

Teeth and kidneys

Colas are highly acidic, around pH 2.5, and frequent sipping softens tooth enamel. Drinking with a meal, using a straw and rinsing with water afterward reduce the effect; brushing immediately after can make erosion worse.

People with chronic kidney disease are usually advised to limit phosphorus, and phosphate additives are one of the main sources to watch. If that applies to you, follow your doctor's or dietitian's guidance.

Bottom line

Phosphoric acid in occasional colas or processed foods is not a concern for healthy people. Daily cola drinkers get the most exposure, and they also get the most sugar, so cutting back helps on both counts.