Sodium sesquicarbonate

INS 500(iii)CAS 533-96-0

Used as an acidity regulator — Codex also lists it as anticaking agent, raising agent, stabilizer, thickener.

Sodium sesquicarbonate is an alkali used to adjust acidity, midway in strength between bicarbonate of soda and washing soda.

Where it is and isn’t permitted

Status of Sodium sesquicarbonate 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 184.1792retrieved 2026-09-07
Codex AlimentariusCodex Alimentarius Commission / JECFAPermitted, with conditions

6 food categories

no numerical limit (good manufacturing practice)

Show every food category
  • 01.2.1.2 Fermented milks (plain), heat-treated after fermentation — GMP
  • 01.4.1 Pasteurized cream (plain) — GMP
  • 01.4.2 Sterilized and UHT creams, whipping and whipped creams, and reduced fat creams (plain) — GMP
  • 01.8.2 Dried whey and whey products, excluding whey cheeses — GMP
  • 09.2.2 Frozen battered fish, fish fillets and fish products, including molluscs, crustaceans, and echinoderms — GMP
  • 12.2.1 Herbs and spices — GMP
CXS 192-1995 Table Three, INS 500(iii)and 6 further provisionsretrieved 2026-09-07

What it is made from

Mined as the mineral trona, or crystallised from sodium carbonate and bicarbonate together.

  • Vegan
  • Vegetarian
CAS registry number
533-96-0
InChIKey
WCTAGTRAWPDFQO-UHFFFAOYSA-K
PubChem
CID 10791

Every name it appears under

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

INS number

  • 500(iii)

CAS registry number

  • 533-96-0
  • 72227-05-5

As it appears in regulation

  • Sodium sesquicarbonate

Other names

  • Carbicarb
  • Carbonic acid, disodium salt, mixt. with monosodium salt
  • Carbonic acid, sodium salt (2:3)
  • CARBONIC ACID, SODIUM SALT, HYDRATE (2:3:2)
  • E-500(III)
  • HSDB 769
  • INS NO.500(III)
  • INS-500(III)
  • Magadi soda
  • Na2CO3 NaHCO3
  • NaHCO3 Na2CO3
  • SESQUI TM
  • Snowfine
  • Snowflake crystals
  • sodium bicarbonate sodium carbonate
  • Sodium carbonate (3:2)
  • Sodium carbonate hydrogen carbonate (3/1/1)
  • sodium carbonate sodium bicarbonate
  • Sodium carbonate sodium hydrogen carbonate
  • sodium hydrogen carbonate sodium carbonate
  • SODIUM MONOHYDROGENDICARBONATE
  • SODIUM SESQUICARBONATE
  • SODIUM-SALT OF CARBONIC ACID
  • SOLVAY T 200
  • SOLVAY T-200
  • Trisodium hydrogendicarbonate
  • trisodium;hydrogen carbonate;carbonate
  • tron a
  • Trona
  • Urao

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
  • gsfa 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/sodium-sesquicarbonate.json