Sodium Ferrocyanide
The short version
An anti-caking agent in table salt — the cyanide is locked in an iron complex, but the name causes regular confusion.
It's permitted and generally considered safe, but there are a few reasons to be mindful — like sensitivities in some people, debated studies, or intake limits. The Safety section below explains the specifics.
Where it comes from
First synthesized in the 18th century. Manufactured by reacting hydrogen cyanide with sodium and iron compounds, producing a stable iron-cyanide coordination complex. Used as a table-salt anti-caking agent since the 1950s.
How it's used
Added to table salt at 10–20 ppm to prevent caking. The cyanide is locked into an iron-cyanide coordination complex that does not release free cyanide under physiological conditions — a fact often misunderstood by consumers reading the name on labels.
Safety profile
ADI of 0.025 mg/kg body weight expressed as ferrocyanide (JECFA). The iron-cyanide complex is one of the most stable known and does not release free cyanide in the digestive tract. The toxicological concern is the complex itself, not cyanide release. Russia banned it in 2018 over uncertainty about long-term iron-cyanide accumulation.
Physical & chemical properties
Yellow crystalline powder, soluble in water. Stable complex of iron(II) with cyanide ligands. Decomposes only at very high temperatures (above 200°C with acid).
Regulation worldwide
Permitted in the EU and US for table salt at controlled levels. Banned in Russia since 2018. Maximum levels per product category strictly enforced.
Educational information only. Not medical or dietary advice.