What is E524?

Sodium hydroxide, also known as caustic soda and, more generically, as lye, is an inorganic compound with the formula NaOH. It is a white solid ionic compound consisting of sodium cations Na+ and hydroxide anions OH−. E524 sits in the E500–E599 series, which in the EU classification mainly covers acidity regulators and anti-caking agents.

What is E524 used for?

E524 belongs to the acids & acidity regulators group. Acids and acidity regulators adjust taste and shelf life, such as citric acid (E330).

Is E524 safe?

E524 is considered safe at the levels used in food and is approved for use in the EU. “Safe” means it is approved in the EU and regarded as safe at the levels used in food.

How E524 appears on labels

On food packaging you'll find E524 either as the number “E524” or by the name “Sodium hydroxide” in the ingredient list, often after its function. Ingredients are listed in descending order by weight, so an additive near the end is present only in small amounts.

Is E524 vegan?

Yes, E524 is suitable for vegans.