E170: Calcium carbonate
What is E170?
Calcium carbonate (E170i) is the same mineral found in chalk, limestone and marble. It is a fine, white, tasteless powder that does not dissolve in water but reacts with acids.
Origin and production
Food-grade calcium carbonate is usually mined and ground from limestone or produced by precipitation from calcium hydroxide and carbon dioxide. Some is also derived from shells, such as oyster shells or eggshells.
Why is it used?
It serves as a white colour, acidity regulator, anti-caking agent and firming agent, and is a common calcium source in fortified foods. It appears in breads, cakes, snacks, protein bars, chewing gum and plant-based milk alternatives.
Vegan, vegetarian and halal
Mineral calcium carbonate is suitable for vegans and vegetarians, but because some supplies come from shells, only the manufacturer can confirm the source; vegan certification resolves the question.
Safety and regulation
E170 is authorised in the EU and was re-evaluated by EFSA. Open Food Facts records no EFSA indication of excessive intake from its use as an additive.
Written by the Foodlas editorial team with AI assistance and checked against EU Regulation (EC) No 1333/2008 and EFSA scientific opinions. Last reviewed: October 14, 2026.
Sources: Regulation (EC) No 1333/2008 · EFSA — Food additives · Wikidata
Common in
Products containing E170
