Sodium hydroxide is the acidity regulator the food industry lists as E524. In our table it is no risk identified: it takes no points off a product's score.
- The key finding, from the FDA: GRAS direct food substance (pH control agent, processing aid) (FDA Substances Added to Food inventory, sodium hydroxide)
- No child flag. The class, and the points it costs, are the same for a child of any age.
- Where you meet it. It turns up in 20 of the 10,000 packaged foods scanned most on Open Food Facts, most often in crackers, cookies and yogurts. Nine in ten of those foods are sold in Europe (counted 26 Sep 2026).
- 2 citations from the FDA and EU law, each one below.
What Sodium hydroxide does to a score
A packaged food's additive subscore starts at 100 and loses points for each additive on the label; that subscore is a third of the final score. Sodium hydroxide takes no points off a product's score. Scan the pack in Sito and the score you get is the one for your own child's age, with this additive named in the reasons. How we score has the whole method.
See what is in your own cupboard
Scan a packaged food and Sito names the additives in it, then scores the product out of 100 for your child's age.
What the sources found
Every classification in our table comes from the citations below, and nothing else. Each finding is our one-line summary of what the source concluded, with the source and reference beside it.
-
FDA
Substances Added to Food inventory — sodium hydroxide
GRAS direct food substance (pH control agent, processing aid). -
EU law
Regulation (EC) No 1333/2008 Annex II
E 524 authorised as an acidity regulator in the EU.
Why this class
Clean current EFSA and FDA status. These rows exist so that an unfamiliar additive is never treated as a bad one: a missing row costs a product nothing, and a clean row says so with citations.
Our confidence in this row's classification is medium. Medium or low does not mean the evidence is weak; it means something about the row is still being pinned down, usually a regulatory status confirmed from one source rather than two.
Questions parents ask
Is Sodium hydroxide (E524) safe for kids?
No risk identified. No regulator finding we score, so a product keeps its full additive subscore in Sito. The current status is clean: GRAS direct food substance (pH control agent, processing aid) (FDA Substances Added to Food inventory, sodium hydroxide).
What is E524?
E524 is the E number for Sodium hydroxide, an acidity regulator. Open Food Facts tags it en:e524.
Next to it on the label
The E numbers either side of E524 in our table, then the closest acidity regulators by number.
- Ammonium sulphate (E517), no risk identified
- Aluminium sulphate (E520), moderate risk, flagged for young children
- Aluminium sodium sulphate (E521), moderate risk, flagged for young children
- Aluminium potassium sulphate (E522), moderate risk, flagged for young children
- Aluminium ammonium sulphate (E523), moderate risk, flagged for young children
- Sodium ferrocyanide (E535), no risk identified