YenzoWhat is E523 (aluminium ammonium sulphate)?
According to Appendix 1 of Circular 24/2019/TT-BYT, aluminium ammonium sulfate (INS 523) has the function firming agent, acidity regulator, colour retention agent, raising agent and stabiliser.
E523Aluminium ammonium sulphate
E523 is aluminium ammonium sulfate. In Appendix 1 of Circular 24/2019/TT-BYT it has the function firming agent, acidity regulator, colour retention agent, raising agent and stabiliser.
- Code
- E523 · INS 523
In Vietnam✓ PermittedOn the list of permitted additives — Circular 24/2019, Appendix 1
Risk level on the Yenzo Scalemoderate?Based on EFSA's scientific assessment, 2008
EFSA (2008) found that intake in some population groups can exceed the tolerable weekly intake (TWI); the EU therefore cut the maximum use levels and removed some of these additives (Regulation (EU) 380/2012). This is what puts it at the middle level of the Yenzo Scale.
How E523 appears on labels
IngredientsIllustrative example
Wheat flour, vegetable oil, salt, sugar, firming agent (523), dried onion and garlic, pepper, natural colour (160a).
firming agent (523)firming agent 523E523INS 523On Vietnamese labels: Nhôm amoni sulfat
Aluminium ammonium sulphate in food
Questions about aluminium ammonium sulphate
Is aluminium ammonium sulphate harmful?
In 2018 EFSA concluded that the aluminium sulphates (E520–E523) are of no safety concern in the current authorised uses and use levels. EFSA noted that they are permitted only in a few specific products, so real exposure is most probably near zero.
Is E523 permitted in Vietnam?
Yes. Aluminium ammonium sulfate (INS 523) is listed in Appendix 1 of Circular 24/2019/TT-BYT, the list of additives permitted in food.
Can children and pregnant women have INS 523?
In 2018 EFSA estimated exposure to aluminium from this group of additives (E520–E523, E541) by age group. In a highly conservative scenario based on the maximum permitted levels, mean exposure in toddlers and children exceeded the TWI of 1 mg aluminium/kg body weight per week. However, because these additives are only authorised in niche products, EFSA considered the estimates highly uncertain and the real exposure most probably near zero, and concluded there is no safety concern at the current authorised uses and use levels. EFSA's conclusions do not single out pregnant women. If you have a particular health condition, ask a doctor.
Other firming agents
E516Calcium sulphatevery lowE518Magnesium sulphatevery lowE520Aluminium sulphatehighE521Aluminium sodium sulphatehighE522Aluminium potassium sulphatehighE526Calcium hydroxidevery low
See all firming agents →Updated 21 October 2026
Sources (3)
- Commission Regulation (EU) No 380/2012 amending Annex II to Regulation (EC) No 1333/2008 as regards the conditions of use and the use levels for aluminium-containing food additives, https://eur-lex.europa.eu/eli/reg/2012/380/oj. EFSA Journal: Safety of aluminium from dietary intake (2008): tolerable weekly intake 1 mg/kg bw.
- Thông tư 24/2019/TT-BYT (văn bản hợp nhất 09/VBHN-BYT), Phụ lục 1
- EFSA Journal (2018). Re-evaluation of aluminium sulphates (E 520-523) and sodium aluminium phosphate (E 541) as food additives