Tricalcium phosphate

About

What it is and where it shows up.

Tricalcium phosphate (TCP) is the tribasic calcium salt of orthophosphoric acid used primarily as a free-flowing (anticaking) agent in powdered food products such as baby formula, table salt, and spice blends. It also functions as a calcium and phosphorus nutritional supplement and is permitted as a raising-agent component in baking powder.

Safety summary

The regulatory and scientific consensus.

EFSA established a group ADI of 40 mg phosphorus/kg body weight/day for all food-additive phosphates including E341(iii), which is considered protective for healthy adults; however, this ADI explicitly does not cover individuals with moderate-to-severe renal impairment. A 2023 PubMed study found that food-grade E341(iii) is largely composed of hydroxyapatite nanoparticles, and nano-objects were identified in baby formula extractions, prompting EFSA to call for revised specifications characterising the nanoparticle fraction. A rat developmental toxicity study reported significant reductions in foetal skeletal measurements and placental weight at high oral doses, warranting caution during pregnancy.

Regulatory landscape

What food-safety regulators have decided.

Jurisdiction	Status	Note
EFSA (European Food Safety Authority) (European Union)	Approved	Approved under Regulation (EC) No 1333/2008 as an anticaking agent and nutrient supplement. Group ADI of 40 mg phosphorus/kg bw/day (shared across all phosphate additives E338–341, E343, E450–452). EFSA recommended the European Commission revise EU specifications to include nanoparticle characterisation (particle size distribution, percentage of particles < 100 nm) for E341(iii); a 2020 EC call for data is ongoing. Authorised in infant formula nutrients under Annex III with carry-over capped at 150 mg/kg as P2O5.source
FSSAI (Food Safety and Standards Authority of India) (India)	Approved	Permitted as INS 341(iii) (Tricalcium orthophosphate) for use in snacks at GMP level under FSSAI Appendix C (Version 2, 2025). Also listed as a permitted ingredient in baking powder under Chapter 2.11 of the Food Safety and Standards (Food Products Standards and Food Additives) Regulations.source
FDA (Food and Drug Administration) (United States)	Approved	Listed as Generally Recognised as Safe (GRAS) under 21 CFR 182.1217 as a multipurpose food substance and dietary supplement. No specific numeric ADI or maximum use level mandated at the federal level.source

Who should approach with care

Whose guidance would steer them away.

Kidney Disease — EFSA explicitly states the group phosphate ADI does not apply to individuals with moderate-to-severe renal impairment, as compromised phosphate excretion can result in hyperphosphataemia with associated cardiovascular and bone complications.

Pregnancy — A rat developmental toxicity study found significant reductions in foetal skeletal measurements and placental weight following high oral TCP doses during gestation, suggesting a need for caution even though no effects were reported in standard EFSA-reviewed developmental studies at ADI-relevant doses.

Infants — Food-grade E341(iii) has been shown to contain nano-scale hydroxyapatite particles identified in baby formula extractions, and the safety of these nanoparticles for infants remains under active EFSA regulatory review with nanoparticle characterisation data still being collected.

Research citations

The sources behind this verdict.

1FDA. 21 CFR 182.1217 – Calcium phosphate, tribasic (GRAS listing). accessdata.fda.gov
2FSSAI. Food Safety and Standards (Food Products Standards and Food Additives) Regulations – Appendix C, Version 2 (2025), 2025. fssai.gov.in
3PubMed. The True Nature of Tricalcium Phosphate Used as Food Additive (E341(iii)), 2023. pubmed.ncbi.nlm.nih.gov
4EFSA. Re-evaluation of phosphoric acid–phosphates – di-, tri- and polyphosphates (E 338–341, E 343, E 450–452) as food additives and the safety of proposed extension of use, 2019. efsa.europa.eu
5PubMed. The effects of maternal exposure to food additive E341 (tricalcium phosphate) on foetal development of rats, 2011. pubmed.ncbi.nlm.nih.gov

Independently researched5 citations