What is it?
Dimethyl dicarbonate (DMDC) is a colourless liquid with a sharp smell, made in a factory from chemicals. Nothing in it comes from animals.
E-numbers / Preservatives / E242
Dimethyl dicarbonate
also: DMDC · Dimethyl pyrocarbonate · Velcorin
A preservative dosed into drinks just before bottling to kill yeast and bacteria. It breaks down within minutes, into carbon dioxide and a little methanol.
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Water, Citric Acid, Flavourings, Acidity Regulator (Trisodium Citrate), Preservatives (Potassium Sorbate, Dimethyl Dicarbonate), Sweetener (Sucralose).
E242
Dimethyl dicarbonate
Dimethyl dicarbonate (DMDC) is a colourless liquid with a sharp smell, made in a factory from chemicals.
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120
of the 43,325 UK supermarket foods we checked declare E242 in their ingredients
That is 0.3%, counted by its code or its name.
Only 23% of these labels print “E242”. Most use the name: look for “dimethyl dicarbonate”.
Counted by NutraSafe from UK supermarket ingredient lists, September 2026. How we counted
How common it is in UK food, by aisle
- Soft drinks and juices69 products2.6% of 2,627
- Alcoholic drinks24 products1.3% of 1,857
- Fruit, vegetables and salad7 products0.3% of 2,631
What dimethyl dicarbonate is, what it does and where you will see it
What does it do?
It gets through the cell walls of yeast, bacteria and mould and switches off enzymes they need to live. It is added to a drink just before filling, then breaks down within minutes at room temperature into carbon dioxide and methanol. Half of it is gone in about 15 minutes at 20 degrees C. By the time the drink reaches you, no DMDC is left.
Where you will see it
Soft drinks, fruit juices, iced teas, sports drinks, flavoured waters, energy drinks, alcohol-free wine, and some wines, ciders and hard seltzers. Because it is gone before you drink it, it is treated as a processing aid in many countries and may not be on the ingredients list. When listed, it reads dimethyl dicarbonate or E242.
What the science says
What it turns into in the drink
Once added, DMDC reacts with water and other substances in the drink within minutes. It mainly turns into carbon dioxide and methanol, with smaller amounts of dimethyl carbonate, methyl ethyl carbonate and a trace of methyl carbamate. None of the DMDC itself is left, so regulators judge the risk from what it turns into.
DMDC breaks down fully in water. The main products are carbon dioxide, methanol, dimethyl carbonate, methyl ethyl carbonate and methyl carbamate. No DMDC is left in treated drinks by the time they are drunk.
2015Regulator reviewEFSA Panel on Food Additives and Nutrient Sources (ANS), Scientific Opinion on the re-evaluation of dimethyl dicarbonate (DMDC, E 242) as a food additive, EFSA Journal 2015, volume 13, 4319
At normal treatment doses, DMDC produces roughly 50mg of methanol per litre of drink, far below levels that cause toxic effects.
1976Lab studyNury et al., Formation of Methanol and Ethyl Methyl Carbonate by Dimethyl Dicarbonate in Wine and Model Solutions, American Journal of Enology and Viticulture
DNA-damage tests
Tests for DNA damage on DMDC itself came back negative, including the standard bacterial test. Methyl carbamate, one of the trace products, did not damage DNA or cause cancer in animal studies. That sets it apart from ethyl carbamate, a different compound found in fermented foods, which IARC classes as probably causing cancer.
DMDC and its main breakdown products tested negative for DNA damage, including in the Ames test and mammalian cell tests.
1991Lab and animal studyJECFA, WHO Food Additives Series 28, Monograph 722: Dimethyldicarbonate (DMDC)
Methyl carbamate, a trace product of DMDC in drinks, did not damage DNA or cause cancer in animal studies, unlike ethyl carbamate, which is classed as probably causing cancer in humans (IARC Group 2A).
2015Regulator reviewEFSA Panel on Food Additives and Nutrient Sources (ANS), Scientific Opinion on the re-evaluation of dimethyl dicarbonate (DMDC, E 242) as a food additive, EFSA Journal 2015, volume 13, 4319
Heavy drinkers of treated drinks and one breakdown product
In their 2015 review, European reviewers found that most breakdown products stay under the threshold they use for trace chemicals. The exception was methyl ethyl carbonate, which could go over it in people who drink a lot of DMDC-treated drinks. They did not see an overall safety issue at current use levels, but noted it as worth watching if use grows.
Intake of DMDC's main breakdown products stays under the threshold of toxicological concern, with one exception: methyl ethyl carbonate in heavy consumers. Reviewers still did not see a safety issue at current use levels.
2015Regulator reviewEFSA Panel on Food Additives and Nutrient Sources (ANS), Scientific Opinion on the re-evaluation of dimethyl dicarbonate (DMDC, E 242) as a food additive, EFSA Journal 2015, volume 13, 4319
Long used to sterilise drinks cold
The international committee found DMDC acceptable for sterilising drinks without heat, at up to 250mg per litre. In long-term animal studies, drinks treated with it caused no visible harm to organs.
Rats given DMDC-treated drinks at high levels for up to 30 months showed no visible harm to organs or tissue.
1991Animal studyJECFA, WHO Food Additives Series 28, Monograph 722: Dimethyldicarbonate (DMDC)
The international committee found DMDC acceptable for sterilising drinks without heat at up to 250mg per litre.
1991Regulator reviewJECFA, 37th Meeting, FAO Food and Nutrition Paper 52 Add.2
Where it stands with the regulators
Approved in the UK and the EU
Daily limit. None set. European reviewers (2015) said the data did not allow one to be worked out, but did not see a safety issue at current use.
- Legal basis
- On the Food Standards Agency's approved list for Great Britain. Commission Regulation (EU) No 1166/2012 extended it to some alcoholic drinks.
- Permitted foods
- Flavoured soft drinks (fizzy drinks, juices, iced teas, sports and energy drinks, flavoured waters) · Alcohol-free wine · Liquid tea concentrates · Ready-to-drink coffee · Alcoholic drinks under 15% alcohol, including beer mixes and hard seltzers
- Maximum levels
- 250mg per litre at the point it is added. None is left in the finished drink.
- History
- The international committee first assessed DMDC in 1991 and found it acceptable up to 250mg per litre. The US FDA allowed it in wine in 1988 at up to 200mg per litre. The EU's Scientific Committee on Food gave an opinion on use in wine in 2001. European reviewers completed a full review in 2015 and kept it approved, noting that methyl ethyl carbonate could pass a precautionary threshold in heavy consumers.
Who should be careful
No UK or EU regulator advises any group to avoid it. Since no DMDC is left in the finished drink, allergy to the additive itself is not a recognised problem. People who drink very large amounts of treated soft drinks every day may want to know methanol is a minor by-product, at levels far below those linked to harm. Look for dimethyl dicarbonate or E242 if it is listed.
The honest read
E242 does one job and then breaks down. The research on DMDC itself has been consistent for decades: negative DNA-damage tests, no cancer signal, no hormone concern and no allergy. The one open question from the 2015 European review is a single breakdown product, methyl ethyl carbonate, which can pass a cautious threshold in people who drink very high amounts of treated drinks. Reviewers did not change the permitted level, and that threshold is a screening tool rather than evidence of harm.
Common questions about dimethyl dicarbonate
Is E242 banned in the UK?
No. E242 is approved in the UK in soft drinks, alcohol-free wine and some alcoholic drinks, at up to 250mg per litre.
Is E242 still in the drink I buy?
No. DMDC breaks down within minutes of being added, with half gone in about 15 minutes at room temperature. By the time the drink is sealed and on the shelf, none is left. What remains are traces of what it turned into: mainly carbon dioxide, methanol, dimethyl carbonate and methyl ethyl carbonate.
What foods contain E242?
Soft drinks, fruit juices, iced teas, sports drinks, flavoured waters, energy drinks, alcohol-free wine, and some wines, ciders and hard seltzers. Because it breaks down before you drink it, makers do not always have to list it, so it may not be on the label even when used.
Is E242 vegan?
Yes. It is made in a factory from chemicals, with nothing from animals.
Sources
- EFSA ANS Panel: Scientific Opinion on the re-evaluation of dimethyl dicarbonate (DMDC, E 242) as a food additive, EFSA Journal 2015;13(12):4319
- JECFA: WHO Food Additives Series 28, Monograph 722: Dimethyldicarbonate (DMDC)
- UK Food Standards Agency: Approved additives and E numbers
- Commission Regulation (EU) No 1166/2012 extending use of E242 in alcoholic beverages
- LANXESS Velcorin: Cold sterilisation systems for beverages
- Nury et al., Formation of Methanol and Ethyl Methyl Carbonate by Dimethyl Dicarbonate in Wine and Model Solutions, American Journal of Enology and Viticulture 27(1):7
- Wikipedia: Dimethyl dicarbonate
Last reviewed: 20 June 2026
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