Calcium carbonate (E 170) as a food additive
What it found
The authors found no need for a numerical daily limit for calcium carbonate itself, but flagged that aluminium unavoidably present in E 170 is a concern.
The work looked at intakes in people, including infants under 16 weeks.
What they found
Studies in people
Clinical studies
Six clinical studies were provided but three were in infants and children with underlying health conditions and were not relevant. In the other three, the amount of calcium carbonate was not given, so exposure could not be assessed.
Animal and lab studies
Small particles
Small particles, including tiny ones, could not be ruled out in E 170. Based on dissolution tests at stomach-like conditions, the authors considered there is no concern from these particles at the concentrations tested.
Animal study
A 90-day study in rats given nano calcium carbonate found no toxicologically relevant effects at the highest dose tested of 1,000 mg per kg body weight per day. The authors noted this study did not look at effects relevant to infants under 16 weeks.
Other findings
Calcium intake from E 170
Calcium from E 170 contributes only a small part of overall calcium intake from the diet. For infants under 16 weeks, estimated exposure to E 170 ranged from 71 to 110 mg per kg body weight per day.
Aluminium in E 170
Aluminium is unavoidably present in E 170. At the highest measured level of 1,120 mg/kg, the tolerable weekly intake for aluminium would be greatly exceeded, up to 890%.
Toxic elements
Levels of lead, cadmium and arsenic in E 170 were substantially lower than current EU limits. The authors say maximum limits for lead, cadmium and arsenic should be lowered, and limits for mercury and aluminium should be introduced.
What the authors conclude
“The Panel concluded that there is no need for a numerical acceptable daily intake (ADI) for calcium carbonate and that, in principle, there are no safety concern with respect to the exposure to calcium carbonate per se at the currently reported uses and use levels in all age groups of the population, including infants below 16 weeks of age.”
Also in their conclusions
- They conclude that there is no need for a numerical acceptable daily intake for calcium carbonate and that, in principle, there are no safety concerns with respect to exposure to calcium carbonate per se at the currently reported uses and use levels in all age groups, including infants below 16 weeks of age.
- They note that the unavoidable presence of aluminium in E 170 is of concern and should be addressed, in the first instance by introducing a limit in the purity criteria.
- They recommend that maximum limits for lead, cadmium and arsenic should be lowered and that limits for mercury and aluminium should be introduced.
How it was done
The authors were asked to fill data gaps from the 2011 safety review and to assess calcium carbonate for infants below 16 weeks of age, a group not covered before.
They reviewed technical and toxicological data submitted by business operators, estimated dietary exposure for all age groups including infants under 16 weeks, and assessed levels of lead, cadmium, arsenic, mercury and aluminium in E 170.
What it can’t tell you
- The clinical studies provided did not give the amount of calcium carbonate, so the authors could not assess exposure from them.
- The animal study did not look at effects relevant to infants under 16 weeks of age.
- The exposure estimates are based on reported use levels and food consumption data, not on measured health outcomes in people.
The paper
- Title
- Re-evaluation of calcium carbonate (E 170) as a food additive in foods for infants below 16 weeks of age and follow-up of its re-evaluation as food additive for uses in foods for all population groups
- Type
- Scientific opinion of the European Food Safety Authority
- Evidence
- Studies in people · animals · lab
- Summarised from
- Full text
- Licence
- CC BY-ND. Words in quotation marks are the authors’; the rest is our summary.
- Cite
- EFSA Panel on Food Additives and Flavourings (FAF), Younes M, Aquilina G, et al (2023). Re-evaluation of calcium carbonate (E 170) as a food additive in foods for infants below 16 weeks of age and follow-up of its re-evaluation as food additive for uses in foods for all population groups. EFSA journal. European Food Safety Authority. doi:10.2903/j.efsa.2023.8106Free full textPubMed 37522100DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error