What is it?
A white mineral that is the main component of limestone and marble. It is quarried and ground into powder or made synthetically as a finer grade. In cosmetics and personal care products it is a mild abrasive in toothpaste, an oil-absorbing, bulking and whitening powder in makeup, and a white colorant (CI 77220). It is also a common food additive (E170) and is used in medicines.
Key information
- The CIR Expert Panel concluded in 2016 that calcium carbonate is safe as used in cosmetics when formulated to be non-irritating.
- In the U.S. it is generally recognized as safe as a food ingredient, with no limit beyond good manufacturing practice.
- The European Food Safety Authority found no safety concern for calcium carbonate itself as a food additive, including in formula for young infants.
- Because it is mined, purity matters; regulators have asked for low levels of heavy metals and aluminium.
More information
Calcium carbonate for industrial use is mined or quarried. Ground calcium carbonate is made by crushing and processing limestone, while precipitated calcium carbonate is made by passing carbon dioxide into a calcium hydroxide solution, which gives a finer, more uniform powder. In the European Union it is an approved cosmetic colorant and must then meet the purity criteria set for it as a food color.
The Cosmetic Ingredient Review (CIR) Expert Panel reviewed it with five other carbonate salts and concluded in its 2016 final report that they are safe as used when formulated to be non-irritating. Calcium carbonate was reported in 174 products, at up to 35 percent in eyebrow pencils and 10 percent in toothpaste, and it did not irritate rabbit eyes. The Panel added the non-irritating condition because some other carbonates in the group irritated skin or eyes in animal tests, and it asked manufacturers to keep heavy metal impurities low.
As a food ingredient, calcium carbonate is generally recognized as safe in the U.S. and can be used with no limit beyond good manufacturing practice. The European Food Safety Authority re-evaluated it in 2011 and followed up in 2023, concluding that no numerical acceptable daily intake is needed and that calcium carbonate itself raises no safety concern at current uses, including in formula for infants under 16 weeks. It did call the aluminium that is unavoidably present in the additive a concern and recommended lower limits for lead and cadmium.
On labels it appears as calcium carbonate or, in color lists, as CI 77220.
Sources: Cosmetic Ingredient Review: Safety assessment of carbonate salts as used in cosmetics (2016); eCFR: 21 CFR 184.1191, Calcium carbonate; EFSA Journal (2023): Re-evaluation of calcium carbonate (E 170) in foods for infants below 16 weeks of age and follow-up for all population groups
