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E242PreservativeModerate concern
Dimethyl Dicarbonate
In plain words
The short version
DMDC — a cold-sterilant beverage preservative that hydrolyzes within hours, leaving methanol and CO2.
Why we flag it amber
It's permitted and generally considered safe, but there are a few reasons to be mindful — like sensitivities in some people, debated studies, or intake limits. The Safety section below explains the specifics.
Safety profile
ADI not specified for the parent; safety based on the rapid hydrolysis to methanol and CO2 — the final beverage contains no DMDC. Methanol residual (~100 mg/L max) is well below natural levels in fruit juices. The pure material is a strong protein-modifier and an occupational-safety hazard during dosing.
The detail
Manufactured by reaction of methyl chloroformate with potassium carbonate. Introduced commercially as Velcorin in the 1970s as a cold-sterilization agent for beverages — kills bacteria and yeasts without heat damage to delicate flavors.
Dosed at 25–250 mg/L immediately before bottle filling. Provides a one-shot sterilization that hydrolyzes within hours, leaving negligible residual. Used in flavored waters, soft drinks, ready-to-drink teas, sports drinks, and some non-alcoholic wines. Common in the US craft-beverage industry.
Colorless liquid with a pungent odor. Very reactive — hydrolyzes rapidly in water (half-life of minutes in aqueous beverage). Stored cold and dosed via automated equipment.
Permitted in the EU, US, Canada, Japan, and most jurisdictions for specific beverage categories. In the EU, DMDC is authorised for use in wine-making under the EU wine rules, and as food additive E 242 it is permitted in drinks such as flavoured drinks, alcohol-free wine, cider and perry, fruit wines and aromatised wines at up to 250 mg/L (ingoing amount, residues not detectable).
Sources
- WHO JECFA database — Dimethyl dicarbonate (INS 242) — Joint FAO/WHO Expert Committee on Food Additives, 1990. ADI not specified; acceptable as cold sterilant up to 250 mg/L
- US eCFR — 21 CFR 172.133 Dimethyl dicarbonate (version of 2026-10-13) — Office of the Federal Register / US FDA, 2026. US permitted in wine (200 ppm), teas and certain beverages (250 ppm)
- EU — Regulation (EC) No 1333/2008 on food additives, Annex II (consolidated text of 18.08.2026) — Publications Office of the European Union, 2026. EU E 242 uses in drinks at 250 mg/L ingoing, residues not detectable
- EU — Commission Delegated Regulation (EU) 2019/934 on authorised oenological practices (consolidated text of 29.12.2024) — Publications Office of the European Union, 2024. DMDC is an authorised oenological practice for wine across the EU
Checked against these sources on .
Educational information only. Not medical, dietary or veterinary advice. Spotted an error? Tell us.