About
What it is and where it shows up.
Calcium sulfate is the calcium salt of sulphuric acid, occurring as an odourless white crystalline powder in anhydrous (CaSO4) or dihydrate (gypsum) form. It is used in food as a firming agent, flour treatment agent, sequestrant, yeast food, and mineral supplement.
Safety summary
The regulatory and scientific consensus.
EFSA's 2019 re-evaluation concluded that exposure to calcium sulfate at reported use levels does not raise a safety concern, with no numerical ADI required. JECFA similarly designates its ADI as 'not limited.' The only notable physiological threshold is a laxative effect observed in humans at approximately 300 mg sulphate/kg body weight per day, a level far exceeded by typical dietary exposure from food additive use.
Regulatory landscape
What food-safety regulators have decided.
| Jurisdiction | Status | Note |
|---|---|---|
| EFSA (European Food Safety Authority) (European Union) | Approved | Authorised under Annex II and Annex III to Regulation (EC) No 1333/2008 as a firming agent, flour treatment agent, sequestrant, and yeast food. Also permitted as a mineral substance in foods for special medical purposes and total diet replacement for weight control under Regulation (EC) No 1925/2006 and Regulation (EU) No 609/2013. No numerical ADI established.source |
| Food Standards Agency (FSA) / Food Standards Scotland (FSS) (United Kingdom) | Approved | Authorised under Assimilated Regulation (EC) No 1333/2008 (retained in GB law post-Brexit) in Annex II and Annex III.source |
| FDA (Food and Drug Administration) (United States) | Approved | Affirmed as Generally Recognized as Safe (GRAS) under 21 CFR 184.1230 for use as a firming agent, leavening agent, nutrient supplement, pH control agent, and processing aid.source |
Who should approach with care
Whose guidance would steer them away.
Kidney Disease — The applicant in EFSA's 2025 health claim review noted that individuals with chronic kidney disease may have interactions with calcium sulfate requiring further investigation, as excess calcium load may be poorly tolerated.
Infants — The EFSA health claim applicant specifically excluded children due to higher nutritional needs for fat and insufficient evidence for benefit or safety of fat-uptake reduction in this population; toddlers also show the highest sulphate exposure per kg body weight in dietary modelling.
Pregnancy — The EFSA 2025 health claim review excluded pregnant and breastfeeding women from the intended target population due to lack of specific safety data for calcium sulfate in these groups at supplemental doses.
Research citations
The sources behind this verdict.
- 1FDA. 21 CFR 184.1230 – Calcium Sulfate (GRAS Affirmation). accessdata.fda.gov
- 2EFSA. Calcium sulphate and reduction in body weight: Evaluation of a health claim pursuant to Article 13(5) of Regulation (EC) No 1924/2006, 2025. efsa.europa.eu
- 3EFSA. Re-evaluation of sulphuric acid and its sodium, potassium, calcium and ammonium salts (E 513, 514(i), 514(ii), 515(i), 515(ii), 516 and 517) as food additive, 2019. efsa.europa.eu
- 4PubMed. Re-evaluation of sulphuric acid and its sodium, potassium, calcium and ammonium salts (E 513, 514(i), 514(ii), 515(i), 515(ii), 516 and 517) as food additive, 2019. pubmed.ncbi.nlm.nih.gov
- 5WHO. JECFA Food Additive Details: Calcium Sulfate (INS 516), 1975. apps.who.int
Independently researched5 citations