Is the stuff that keeps salt from clumping safe?
Re‐evaluation of sodium ferrocyanide (E 535), potassium ferrocyanide (E 536) and calcium ferrocyanide (E 538) as food additives
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Surprising Findings
Ferrocyanide is made with cyanide but doesn’t act like a poison
Most people associate cyanide with acute toxicity and death, but ferrocyanide is so stable it doesn’t release free cyanide in the gut. The body treats it like inert material.
Practical Takeaways
Don’t panic if you see 'sodium ferrocyanide' on a salt label — it’s safe at current levels.
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Surprising Findings
Ferrocyanide is made with cyanide but doesn’t act like a poison
Most people associate cyanide with acute toxicity and death, but ferrocyanide is so stable it doesn’t release free cyanide in the gut. The body treats it like inert material.
Practical Takeaways
Don’t panic if you see 'sodium ferrocyanide' on a salt label — it’s safe at current levels.
Publication
Journal
EFSA Journal
Year
2018
Authors
M. Younes, P. Aggett, F. Aguilar, Riccardo Crebelli, B. Dusemund, M. Filipič, M. Frutos, P. Galtier, D. Gott, U. Gundert-Remy, G. Kuhnle, C. Lambré, J. Leblanc, I. T. Lillegaard, P. Moldéus, A. Mortensen, A. Oskarsson, I. Stanković, I. Waalkens-Berendsen, M. Wright, A. di Domenico, Henk van Loveren, A. Giarola, Z. Horváth, F. Lodi, R. Woutersen
Related Content
Claims (6)
The kidneys are the main organ affected by too much sodium ferrocyanide, and in rat studies, up to 4.4 mg per kg of body weight per day didn’t cause lasting harm — though there were small, temporary signs of kidney changes.
Those anti-caking additives in salt (like E 535) don’t damage DNA or cause cancer, according to lab tests and long-term rat studies, so they’re considered safe to eat.
The amount of ferrocyanide you get from eating table salt is super low—even if you eat a lot of salt, you're still way under the safety limit.
Experts say it's safe to eat up to 0.03 milligrams of ferrocyanide per kilogram of your body weight every day — they figured this out using rat studies and added a big safety buffer.
When people eat ferrocyanides, their bodies absorb only a tiny amount—less than half a percent—and it doesn’t build up inside them, so very little actually gets into the system.