Dimethyl dicarbonate

E number E242INS 242CAS 4525-33-1

Used as a preservative.

Dimethyl dicarbonate is a cold sterilant for beverages, added just before bottling to kill yeasts and moulds without heating the drink. It breaks down to methanol and carbon dioxide within hours.

Where it is and isn’t permitted

Status of Dimethyl dicarbonate by jurisdiction. Every jurisdiction this site covers is listed, including those where the substance does not appear.
JurisdictionStatusScope and limitsCitation
United StatesFood and Drug AdministrationPermitted, with conditions21 CFR 172.133retrieved 2026-09-07
Codex AlimentariusCodex Alimentarius Commission / JECFAPermitted, with conditions

8 food categories

highest permitted level 250 mg/kg

Show every food category
  • 14.1.2 Fruit and vegetable juices — 250 mg/kg
  • 14.1.3 Fruit and vegetable nectars — 250 mg/kg
  • 14.1.4 Water-based flavoured drinks, including "sport," “energy,” or "electrolyte" drinks and particulated drinks — 250 mg/kg
  • 14.1.5 Coffee, coffee substitutes, tea, herbal infusions, and other hot cereal and grain beverages, excluding cocoa — 250 mg/kg
  • 14.2.2 Cider and perry — 250 mg/kg
  • 14.2.3 Grape wines — 200 mg/kg
  • 14.2.4 Wines (other than grape) — 250 mg/kg
  • 14.2.5 Mead — 200 mg/kg
CXS 192-1995 Table One, INS 242and 7 further provisionsretrieved 2026-09-07

What it is made from

A synthetic compound made from methanol and phosgene chemistry. It is designed to disappear: it is not present in the drink by the time it is opened.

  • Vegan
  • Vegetarian
CAS registry number
4525-33-1
InChIKey
GZDFHIJNHHMENY-UHFFFAOYSA-N
PubChem
CID 3086

Every name it appears under

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

E number

  • E242

INS number

  • 242

CAS registry number

  • 4525-33-1

As it appears in regulation

  • Dimethyl dicarbonate

Other names

  • Baycovin; DEPA;Dekapex; Diethyl dicarbonate;Ue 5908
  • Dicarbonic acid, 1,3-dimethyl ester
  • Dicarbonic acid, C,C'-dimethyl ester
  • Dicarbonic acid, dimethyl ester
  • Dimethyl dicarbonate
  • Dimethyl dicarbonate, for histidine methylation
  • Dimethyl oxydiformate
  • Dimethyl pyrocarbonate
  • Dimethyl pyrocarbonate; Methyl pyrocarbonate; Pyrocarbonic acid dimethyl ester; Velcorin
  • Dimethyldicarbonate
  • dimethylpyrocarbonate
  • DMDC
  • E 242
  • Formic acid, oxydi-, dimethyl ester
  • Formic acid, oxydi-, dimethyl ester (7CI,8CI)
  • HSDB 8117
  • INS NO.242
  • INS-242
  • methoxycarbonyl methyl carbonate
  • methoxycarbonyl methyl carbonate;DMPC Dimethyl pyrocarbonate Pyrocarbonic acid dimethyl ester;
  • Methyl pyrocarbonate
  • Pyrocarbonic acid dimethyl ester
  • Velcorin

Systematic names

  • methoxycarbonyl methyl carbonate

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/dimethyl-dicarbonate.json