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E516AcidulantLow concern
Calcium Sulfate
In plain words
The short version
Food-grade gypsum — a firming agent and the classic coagulant that sets soy milk into tofu.
Why it's green
It's widely considered safe at the amounts used in food, so we mark it green. The Safety section below has the details.
Safety profile
No ADI specified. Poorly soluble and largely unabsorbed; a useful calcium source.
The detail
The mineral gypsum (or anhydrite). Partially dehydrated, it is 'plaster of Paris'.
Firming agent, dough conditioner, and calcium source — and the classic coagulant that sets soy milk into tofu. Also a free-flow aid and a yeast nutrient in brewing and baking.
White powder, slightly soluble in water; the hemihydrate ('plaster') sets hard when mixed with water.
Permitted in the EU, the US (GRAS), and globally.
Sources
- WHO JECFA database — Calcium sulfate (INS 516) — Joint FAO/WHO Expert Committee on Food Additives (WHO), 1973. Safety: no numerical ADI; firming agent / yeast food functions
- 21 CFR 184.1230 — Calcium sulfate (eCFR, current as of 13 Oct 2026) — US eCFR / Office of the Federal Register, 2026. Origin (gypsum/plaster of Paris) and US GRAS status
- EUR-Lex — Regulation (EC) No 1333/2008 on food additives, consolidated version of 18 August 2026 — Publications Office of the European Union, 2026. Regulation: permitted in the EU
Checked against these sources on .
Educational information only. Not medical, dietary or veterinary advice. Spotted an error? Tell us.