E524Sodium hydroxide

E524 is sodium hydroxide. In Appendix 1 of Circular 24/2019/TT-BYT it has the function acidity regulator.

Code: E524 · INS 524
Group: Acidity regulator

In Vietnam✓ PermittedOn the list of permitted additives — Circular 24/2019, Appendix 1

Risk level on the Yenzo Scalevery low?Based on the Open Food Facts additives taxonomy

How E524 appears on labels

IngredientsIllustrative example

Wheat flour, vegetable oil, salt, sugar, acidity regulator (524), dried onion and garlic, pepper, natural colour (160a).

acidity regulator (524)acidity regulator 524E524INS 524On Vietnamese labels: Natri hydroxyd

Questions about sodium hydroxide

What is E524 (sodium hydroxide)?

According to Appendix 1 of Circular 24/2019/TT-BYT, sodium hydroxide (INS 524) has the function acidity regulator.

Is sodium hydroxide harmful?

The FAO/WHO expert committee JECFA last evaluated sodium hydroxide in 1965 and recorded the ADI as “not limited”. This is a JECFA conclusion, not an EFSA one; the JECFA summary gives no intake figures.

Is E524 permitted in Vietnam?

Yes. Sodium hydroxide (INS 524) 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 524?

In the EU, Annex II Part E of Regulation (EC) No 1333/2008, category 13.1.3 (processed cereal-based foods and baby foods), lists sodium hydroxide (E524): no maximum level (quantum satis), only processed cereal-based foods and baby foods, only for pH adjustment. The text has no separate rule for pregnant women. If you have a particular health condition, ask a doctor.

Other acidity regulators

E523Aluminium ammonium sulphatemoderate E525Potassium hydroxidevery low E526Calcium hydroxidevery low E527Ammonium hydroxidevery low E528Magnesium hydroxidevery low E529Calcium oxidevery low

See all acidity regulators →

Updated 21 October 2026

How Yenzo scores

Sources (4)

Open Food Facts additives taxonomy (Yenzo's table cites no EFSA opinion for this code). Open Food Facts additives taxonomy, https://github.com/openfoodfacts/openfoodfacts-server/blob/main/taxonomies/additives.txt (entry en:e524)
Thông tư 24/2019/TT-BYT (văn bản hợp nhất 09/VBHN-BYT), Phụ lục 1
JECFA (FAO/WHO), Summary of Evaluations: Sodium hydroxide (INS 524)
Regulation (EC) No 1333/2008 on food additives, Annex II Part E (consolidated version of 18.08.2026) - 13.1.3 Processed cereal-based foods and baby foods

Information only, not medical advice. The risk level is the additive's class in Yenzo's open scoring method, based on the cited source.