E500 – Sodium Carbonates (i, ii, iii)

Safety grading GREEN – SAFE

E500 represents a family of sodium carbonate salts used in food as pH regulators, leavening agents and anti-caking agents. These include E500(i) sodium carbonate, E500(ii) sodium hydrogen carbonate (commonly known as baking soda) and E500(iii) sodium sesquicarbonate. The safety of these compounds has been well studied and consistently confirmed by major regulators. EFSA allows sodium carbonates at quantum satis, indicating no numerical Acceptable Daily Intake (ADI) is necessary due to their low toxicity. The U.S. FDA lists sodium carbonate and sodium bicarbonate as GRAS (Generally Recognized as Safe) for direct food use. This classification is reserved for substances with strong evidence of safety at current levels of application.

Independent toxicological reviews show no carcinogenicity, no mutagenicity and no reproductive toxicity at realistic exposure levels. Even in studies where animals consumed extremely high doses, effects were limited to transient digestive discomfort or mild metabolic alkalosis – far beyond what ordinary food consumption could produce. E500(ii), in particular, has a long history of medicinal use as an antacid, further demonstrating its benign toxicological profile. It is well tolerated by the body and breaks down into carbon dioxide, sodium ions and water.

Some considerations exist for individuals on sodium-restricted diets. Since all E500 compounds contribute sodium, consumers with hypertension or kidney disease should be mindful of total sodium intake, but the contribution from additives is generally small compared with table salt. People with sensitive stomachs may occasionally experience discomfort from large supplemental intakes of bicarbonate, but such effects are not associated with levels used in food products. No credible evidence suggests E500 is harmful at permitted usage levels, so it receives a GREEN – SAFE classification.

Should you avoid E500?

There is no reason for the general population to avoid E500. Sodium bicarbonate and sodium carbonate have been used for decades in baking, drinks, snacks and desserts. For most consumers, the primary health consideration is overall dietary sodium. The sodium content added by E500 in most foods is minimal compared with salt added during cooking or present in processed foods. Individuals who must restrict sodium for medical reasons should remain aware of all sodium sources but can consume typical levels of E500 without concern.

Baking soda is widely consumed and even recommended clinically for occasional heartburn relief, demonstrating the very low risk of the compound. There are no known allergy risks associated with E500 and no credible reports of toxicity at food-level intake. People with extremely sensitive digestive systems may prefer to avoid very high bicarbonate-containing supplements, but normal food exposure is far below such levels.

Common uses

Leavening in baked goods such as cakes, muffins, cookies and pancakes.
A key ingredient in baking powder, reacting with acidulants to release CO₂.
pH regulation in cocoa processing, helping to develop flavour and colour.
Anti-caking functions in powdered spices, sugar mixes and instant beverages.
Effervescence in fizzy tablets, powdered drinks and sherbet products.
Improves texture and browning in crackers and some savoury snacks.
Used in seafood processing, particularly for tenderisation in some regions.

Common names / Synonyms

Sodium carbonate
Sodium bicarbonate
Baking soda
Sodium sesquicarbonate
Soda ash (non-food applications)
Sodium salts of carbonic acid

What is it?

E500 additives are inorganic sodium salts of carbonic acid. They can be obtained from natural mineral deposits such as trona or natron, or produced through chemical processes. Sodium carbonate (E500(i)) is strongly alkaline and used primarily to regulate acidity. Sodium hydrogen carbonate (E500(ii)), better known as baking soda, releases carbon dioxide when heated or when mixed with an acid. This CO₂ production is the basis of its leavening effect in baking. Sodium sesquicarbonate (E500(iii)) is a double salt that contains both carbonate and bicarbonate ions, providing intermediate functionality between the two.

Industrial production includes the Solvay process, which reacts sodium chloride with ammonia and carbon dioxide to yield sodium carbonate. Baking soda can then be produced by carbonating sodium carbonate solutions. These reactions are predictable, well understood and produce compounds with high purity suitable for food use. All forms of E500 are white, odourless powders with excellent solubility in water.

Functionally, sodium carbonates serve multiple purposes in food technology. They regulate acidity, improve browning reactions, stabilise dry mixtures, and generate gas for aeration. Their simple chemistry and well-known behaviour make them dependable ingredients in industrial and home baking. The human body handles carbonates and bicarbonates efficiently through natural buffering and exhalation of carbon dioxide.

Where it’s allowed (EU vs US)

E500 is fully permitted in the European Union, the United States, Canada, Australia, New Zealand and most other global regulatory systems. In the EU, it is authorised at quantum satis across many food categories. In the U.S., baking soda and sodium carbonate are GRAS and widely used in processed and home-prepared foods.