Magnesium Carbonate
The short version
A light mineral powder used to keep salt and powders free-flowing, regulate acidity, and 'Dutch' cocoa.
It's widely considered safe at the amounts used in food, so we mark it green. The Safety section below has the details.
Where it comes from
The mineral magnesite, or precipitated from magnesium salts. Chemically MgCO3.
How it's used
Anti-caking and free-flow agent (table salt, spices, powdered foods), acidity regulator, and a source of magnesium. Alkalizes cocoa in the 'Dutch process'. It is also the 'chalk' used by climbers and gymnasts.
Safety profile
No ADI specified. Poorly absorbed; larger amounts act as an antacid and mild laxative.
Physical & chemical properties
Light, bulky white powder, practically insoluble in water, reacting with acids to release CO2.
Regulation worldwide
Permitted in the EU, the US (GRAS), and globally.
Educational information only. Not medical or dietary advice.