E520 · Firming agents

Aluminium sulphate

High risk

Best avoided due to concerns over dietary aluminum accumulation.

Category: Firming agents
Vegan: Yes
Vegetarian: Yes

What it is

Aluminium sulphate is a light-metal salt used to firm texture and fix colour, most often in egg-white preparations.

How it is used in food

Firms egg-white foam and stabilises colour.

Commonly found in

Pickled vegetables (historical)
Candied fruits

Health and safety

Aluminium accumulates in bone and tissue and clears slowly. EFSA set a tolerable weekly intake of 1 mg per kg of body weight, and dietary surveys in parts of Europe found that some people — children especially — already meet or exceed it from food alone. That is the argument for avoiding avoidable sources, rather than any finding that this additive is acutely harmful.

Concerns exist regarding cumulative aluminum toxicity and its potential link to neurological disorders.

Aluminium Accumulation

General population · evidence: suspected

Aluminium from food additives can accumulate in the body over time, which has been controversially linked to neurological conditions.

Authorised in the EU, with its permitted uses narrowed substantially in 2012 to reduce total dietary aluminium. EFSA's tolerable weekly intake is 1 mg/kg body weight.

Regulatory status

Region	Status	Notes
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: E520

Also printed asAluminium sulfate · aluminum sulfate · aluminum sulphate

Worth knowing

The EU cut back the aluminium additives sharply in 2012 for exactly this reason — not because any one of them was dangerous, but because together they added up.

Conclusion

Best avoided due to concerns over dietary aluminum accumulation.

References

EFSA Safety Assessment

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Entry last reviewed 2026-07-28.

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