What is E521?
E521 is Aluminium sodium sulphate, a food additive used as a firming agent. A mineral, so there is no animal, pork or alcohol source.
Also written as: INS 521, E-521, E 521. INS is the international numbering system used outside Europe, including on labels in Asia, Australia and the Middle East.
What to do
No action needed for this additive. Check the rest of the ingredient list, and remember that meat products still need proper halal slaughter.
Is E521 vegetarian or vegan?
Yes. E521 (Aluminium sodium sulphate) is normally made from plant, mineral, microbial or synthetic sources, so it is suitable for vegetarians and vegans.
Why we classify it this way
Halal A mineral, so there is no animal, pork or alcohol source.
Basis: No concern found. Made from plants, minerals, fermentation or synthesis, or from a permitted animal product. Nothing in normal production raises a pork, alcohol, insect or slaughter question.
No external reference is listed for this record yet.
Classification audited 3 November 2026. It has not been reviewed by a scholar. How classifications work · Suggest a correction
Frequently asked questions
Is E521 halal?
E521 (Aluminium sodium sulphate) is halal. A mineral, so there is no animal, pork or alcohol source.
What is E521 made from?
Mineral salt.
What is E521 used for?
E521 is used as a firming agent.
What should I do if a product contains E521?
No action needed for this additive. Check the rest of the ingredient list, and remember that meat products still need proper halal slaughter.
Is E521 vegetarian or vegan?
Yes. E521 (Aluminium sodium sulphate) is normally made from plant, mineral, microbial or synthetic sources, so it is suitable for vegetarians and vegans.