E170: Calcium Carbonate (Mineral White Color / Anti-Caking)

Direct Answer

E170 (Calcium Carbonate / CaCO3) is a fine mineral salt mined from limestone or precipitated synthetically. INS 170(i), ADI is Not Limited (Quantum Satis), serving as a white surface colorant, acidity buffer, anti-caking agent, and calcium nutrient fortificant.

Source: EFSA / Codex Alimentarius · Last reviewed Aug 28, 2026

Specs

E-Number Code	E170
INS / Codex Number	INS 170(i)
Functional Class	Food Color (White / Opacifier), Anti-Caking, Acidity Regulator, Nutrient
Acceptable Daily Intake (ADI)	Not Limited (Quantum Satis)
Chemical Formula	CaCO3
Primary Mechanism	High refractive index light scattering creating white opacity; neutralizes acids to calcium salts and CO2
Common Target Foods	Chewing gum coatings, plant milks (Soy/Almond calcium fortification), baking powders, tablets
Dietary Compliance	Vegan (Mineral limestone), Halal, Kosher
Safety Approval	EFSA Authorized / FDA GRAS (21 CFR 184.1191)

Titanium Dioxide (E171) Replacement

Following the EU ban on E171 (Titanium dioxide) due to nanoparticle genotoxicity concerns, ultrafine-milled E170 calcium carbonate has become the global benchmark for natural white opacity in confectionery and coatings.