Food additive databaseprocessing agentChecked 2026-10-02

Sodium Hydroxide (Caustic Soda) 水酸化ナトリウム（別名カセイソーダ）

Designated additivePermitted in the EU (E524)

Purpose: processing agent
On the label: “水酸化ナトリウム” (sodium hydroxide), “カセイソーダ” (caustic soda) (labeling is exempt when it counts as a processing aid)
Name in the List of Designated Additives: 水酸化ナトリウム（別名カセイソーダ） (No. 234)

In Japan

A strong alkali, used as a manufacturing agent in food production processes.
The standards for use require that it be neutralized or removed before the final food is completed.
When it counts as a processing aid that does not remain in the final food, labeling is exempt.

Japan's standards for use

Must be neutralized or removed before the final food is completed

This is a summary of the standards for use. See the source list for the exact conditions.

In the EU

It is on the EU list of food additives (Regulation (EC) No 1333/2008, Annex II) as E524.

Sources

Checked 2026-10-02. Rules and evaluations change over time. This page is a translation of our Japanese page; if they differ, the Japanese page is the reference.

This page lists facts stated in laws and in evaluations by public bodies; it is not a safety verdict. Additives used in Japan are approved by the government, which sets the foods and amounts they can be used in. The ADI is a guide to the amount that is considered safe to take every day over a lifetime.

Other substances used as processing agent

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