Bentonite

E number E558CAS 1302-78-9

Bentonite is a clay used to clarify wine, beer and juice: it binds haze-forming proteins and is then filtered out. It is a processing aid rather than an ingredient of the finished drink.

Where it is and isn’t permitted

Status of Bentonite by jurisdiction. Every jurisdiction this site covers is listed, including those where the substance does not appear.
JurisdictionStatusScope and limitsCitation
United StatesFood and Drug AdministrationPermitted21 CFR 184.1155retrieved 2026-09-07
Codex AlimentariusCodex Alimentarius Commission / JECFANot listedDoes not appear on this jurisdiction’s permitted list. That is not the same as being prohibited.

What it is made from

Mined volcanic clay, chiefly montmorillonite, then purified and milled. Because it is removed before bottling it is one of the reasons a wine may or may not be vegan — bentonite is mineral, but other fining agents are not.

  • Vegan
  • Vegetarian
CAS registry number
1302-78-9

Every name it appears under

6 recorded names. A label may use any of them.

E number

  • E558

CAS registry number

  • 1302-78-9

As it appears in regulation

  • Bentonite

Other names

  • Bentonite
  • E 558

Systematic names

  • Dioxosilane; oxo(oxoalumanyloxy)alumane; hydrate

Hazard reference values

No reference value for this substance in the sources we hold.

Evidence and how bodies read it

Studies, and the differing conclusions regulators drew from them, are curated by hand rather than machine-read, and none has been written for this substance yet.

Sources for this page

  • ecfr retrieved 2026-09-07

Full licence terms and publisher details on Sources. How this page is built and updated: Method.

Machine-readable:/api/v1/additives/bentonite.json