E535 Sodium ferrocyanide

E535Anti-caking agentsOrigin: Lab-made

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The short answer

Sodium ferrocyanide (E535) keeps table salt from clumping in humid weather. Its cyanide is locked inside the molecule and is not released in normal cooking, but it is one of the few additives with a cyanide name.

60/100

Use in moderation

Safe in small amounts; may bother some people or raise blood sugar.

E-numberE535

Comes fromLab-made

What it doesAnti-caking agents

Glycemic index—

Daily limitNot set

Also calledSodium ferrocyanide, Yellow prussiate of soda

Rules by country

🇺🇸 US FDAApproved with limits

🇪🇺 European UnionApproved with limits

🇨🇦 Health CanadaApproved with limits

CaliforniaNo extra rules

The US allows it in table salt at very low levels as an anti-caking agent. The EU permits it in salt at a set maximum. Its cyanide is tightly bound and not free, so the concern is about breakdown under strong heat or light.

Daily limit: Experts haven’t set a number because normal food amounts are far below any level of concern.

What is it?

This white crystalline salt is added in tiny amounts so salt pours freely. It is far less toxic than free cyanide because the iron holds the cyanide tightly. The main concern is decomposition, which can happen under strong sunlight or very high heat.

Where it comes from: Made by an industrial process that combines iron, cyanide and sodium into a stable complex. The cyanide is held tightly inside the molecule.

Why it’s in food

Keeps table salt pouring
Stops salt from clumping in humid weather
Used at very low levels

Often found in

Table saltIodized salt in some countriesSalt blendsSeasoned salts

Also listed as: Sodium ferrocyanide, Yellow prussiate of soda, Sodium hexacyanoferrate, Ferrocyanide

Health & gut impact

Bound cyanideUnder study

The cyanide in sodium ferrocyanide is held tightly by iron, so it is not released in normal digestion. Strong light or very high heat can break it down, which is why limits are set.

FAO/WHO JECFA evaluation of ferrocyanides

Low doseBenefit

The amount in salt is very small, far below the level that would matter for a healthy adult.

EU Regulation (EC) No 1333/2008

Salt without anti-caking agents

Clean-label swaps

Clean grocery swap

Fine sea salt, single ingredient

Listed as salt only.

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Clean grocery swap

Kosher salt

Coarse salt with no flow agents.

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Pantry swap

Ceramic salt cellar

Keeps salt dry without any additive.

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What can I use instead?

Plain sea salt

Ratio: 1:1

Best for: Salt without anti-caking agents

Rice in the shaker

Ratio: A few grains

Best for: Keeping salt dry at home

More anti-caking agents:

Calcium Phosphates (Tricalcium Phosphate) E341Calcium phosphates (E341) keep powders flowing, make baking powder rise and add calcium to plant milks. They're safe for most people, but phosphate additives add up, which matters for anyone with kidney disease.Use in moderation Dimethylpolysiloxane E900Dimethylpolysiloxane (E900) is a food-grade silicone that stops frying oil from foaming. It sounds alarming, but it's used at a few parts per million and passes through the body unabsorbed.Use in moderation Magnesium carbonate E504Magnesium carbonate (E504) is a fine mineral powder that keeps table salt and spice blends free-flowing. It's vegan, gluten-free and safe at the small levels used in food.Generally safe Magnesium stearate E572Magnesium stearate (E572) is a fine powder that stops powders and supplement tablets from sticking to machines. It is approved in food and supplements, and it is vegan only when the fat behind it is plant-based.Generally safe

Common questions

Is there cyanide in table salt?

Only as a tightly bound complex in tiny amounts. It is not free cyanide, and the dose in salt is far below harmful levels.

Is Sodium ferrocyanide safe?

Use in moderation (60/100). The US allows it in table salt at very low levels as an anti-caking agent. The EU permits it in salt at a set maximum. Its cyanide is tightly bound and not free, so the concern is about breakdown under strong heat or light.

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Scientific sources & regulatory citations

EFSA OpenFoodTox: E535
FAO/WHO JECFA evaluation of ferrocyanides
EU Regulation (EC) No 1333/2008

INS 535 · CAS 13601-19-9