E502 - Carbonates

At a glance

• What it is: A group of carbonate salts used as acidity regulators and leavening agents
• Where you’ll see it: Baking powders, biscuits, crackers, waffles, and some confectionery
• Why it’s used: To neutralize acids and release gas for light, crisp textures
• Regulatory status: Authorized in the EU with compositional and purity specifications¹²

Why is Carbonates added to food?

Carbonates balance acidity and help dough rise. As acidity regulators, they adjust pH so foods taste right and stay stable. As leavening agents, they release gas when heated or when mixed with acids, which makes baked goods airy and crisp.²

In recipes and industrial baking, carbonate salts are often paired with an acid source (like cream of tartar or sodium acid pyrophosphate) to form “double-acting” baking powders. That pairing controls when and how much gas is released, improving texture and volume.²

What foods contain Carbonates?

You’ll most often find E502 in low-moisture baked goods and mixes where a light, crisp bite is desired. Typical examples include:

• Crackers, biscuits, cookies, and waffle cones
• Baking powder blends and dry baking mixes
• Some confectionery and specialty breads

In practice, manufacturers may use specific carbonate salts such as sodium carbonates, potassium carbonates, ammonium carbonates, or magnesium carbonates, choosing the one that best fits the product’s flavor, texture, and labeling needs.²

What can replace Carbonates?

Alternatives depend on the job you need done:

• For leavening: Baking powders based on sodium carbonates or potassium carbonates paired with acids; yeast; steam-leavened methods (e.g., choux pastry).
• For acidity control: Citric acid (citric acid) or other permitted acidulants and buffering salts, chosen to match flavor and pH targets.²

Keep in mind that swapping one carbonate for another changes sodium or potassium content and can affect taste and browning.

How is Carbonates made?

Food-grade carbonate salts are produced and purified to meet legally defined specifications. In general, they are obtained by reacting carbon dioxide (CO2) with appropriate alkaline bases to form carbonate or hydrogen carbonate (bicarbonate) salts, followed by filtration and drying. Their identity, purity, and contaminants limits are set out in EU additive specifications.¹

Is Carbonates safe to eat?

Carbonates are authorized food additives in the European Union, where they must meet purity criteria and are allowed only in specified foods and under defined conditions. This authorization reflects a safety evaluation by regulators for the intended uses.¹²

As with many common additives, overall safety depends on the specific salt (for example, sodium vs. potassium) and the use level in the final food. When used as permitted, carbonate salts serve technological purposes without changing the nature of the food beyond their function.²

Does Carbonates have any benefits?

Yes. Carbonates:

• Improve rise and texture in baked goods by generating gas during mixing and baking
• Help fine-tune acidity (pH), which can influence flavor, color, and shelf life
• Support consistent product quality across batches²

Who should avoid Carbonates?

Most people do not need to avoid carbonate additives used as intended. However:

• If you manage sodium or potassium intake (for example, for blood pressure or kidney conditions), check the ingredient list to see which carbonate salt was used—sodium carbonates add sodium, while potassium carbonates add potassium.
• Individuals with medically prescribed low-magnesium diets should note that magnesium carbonates can be used as anti-caking agents in some foods.

If you are unsure which specific carbonate is present, look for the full ingredient name alongside or instead of the E-number.

Myths & facts

• “Carbonates are the same as baking powder.” Not quite. Carbonates are one part of baking powder; the other essential part is an acid source that makes the leavening reaction predictable.
• “Carbonates are unsafe chemicals.” Carbonate salts have well-defined food-grade specifications and are authorized for use in many foods when used as intended.¹²
• “All carbonates taste the same.” Different cations (sodium, potassium, ammonium, magnesium) can subtly change taste, browning, and texture, so bakers choose them carefully.

Carbonates in branded foods

On packages, you might see “E502,” “carbonates,” or the specific salt name (such as potassium bicarbonate or ammonium bicarbonate). Expect to find them in crackers, cookies, wafer cones, baking powders, and some sweet goods where a dry, crisp texture is desired.²

References

Footnotes

1. Commission Regulation (EU) No 231/2012 laying down specifications for food additives listed in Annexes II and III to Regulation (EC) No 1333/2008 — EUR-Lex. https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:32012R0231 ↩ ↩² ↩³ ↩⁴

2. Regulation (EC) No 1333/2008 on food additives (and subsequent amendments establishing the Union list and conditions of use) — EUR-Lex. https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:32008R1333 ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰