ScanWise
E534 · Anti-caking agents

Iron (III) meso-Tartrate

No known risk

A highly specific additive that prevents salt from caking in humid environments.

Category
Anti-caking agents
Vegan
Yes
Vegetarian
Yes

What it is

An iron salt of tartaric acid used specifically as an anti-caking agent for salt.

How it is used in food

Prevents table salt from clumping in humid conditions by interfering with the growth of interlocking salt crystals, keeping it free-flowing without the ferrocyanide-based agents used previously.

Commonly found in
  • Table salt

Health and safety

Approved by EFSA as safe for use in salt up to specific limits.

EFSA's 2015 scientific opinion concluded that iron(III) meso-tartrate is of no safety concern at the proposed use level of 106 mg/kg in salt. The iron is barely absorbed in this form, and tartrate is a well-characterised, naturally occurring food acid component.

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
E534

Worth knowing

It is one of the newest additives on the EU list, authorised in 2015 specifically as a modern alternative to the long-established ferrocyanide anti-caking agents (E535–E538) in salt.

Conclusion

A highly specific additive that prevents salt from caking in humid environments.

Is it in what you are buying?

ScanWise reads the barcode and tells you which additives a product actually contains, and what they do to its score.

Open the app

Entry last reviewed 2026-07-28.

← All additives