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E536

Potassium ferrocyanide

Limited risk

Anti-caking agent in salt.

Vegan
Yes
Vegetarian
Yes

What it is

A highly effective anti-caking agent used specifically in table salt.

How it is used in food

Prevents table salt from clumping together into a solid block, ensuring it flows freely even in humid environments.

Commonly found in
  • Table salt
  • Sea salt
  • Road salt

Health and safety

Safe at regulated levels. Despite the scary "cyanide" name, the cyanide molecules are so tightly bound to the iron atom that they cannot be released or absorbed by the human body.

Evaluated by EFSA and confirmed safe for use in food at authorized levels.

Regulatory status

RegionStatusNotes
Australia & New Zealand
FSANZ
Permitted Permitted under the FSANZ Food Standards Code.
European Union
EFSA / European Commission
Permitted Authorised for food use under EU regulations (Annex II).
United States
FDA (Food and Drug Administration)
Permitted Authorised for food use by the FDA (often GRAS for standard additives).

Identification on labels

E-number
E536

Worth knowing

The chemical bond between the iron and cyanide is incredibly strong — even stomach acid cannot break it to release toxic cyanide.

Conclusion

Potassium ferrocyanide is a limited concern that is safe within regulated dietary amounts. Although the name mentions cyanide, the molecules are chemically locked to iron atoms and cannot be absorbed or set free in your body. EFSA has confirmed it is safe for keeping table salt free-flowing.

References

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Entry last reviewed 2026-07-28.

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