E242 - Dimethyl dicarbonate

At a glance

• What it is: A fast-acting beverage preservative also called DMDC.
• What it does: Inhibits yeast and bacteria during processing; it does not give long-term protection.
• Where it’s used: Soft drinks, iced teas, juice drinks, sports drinks, and some wines.
• How it behaves: It hydrolyzes (breaks down) rapidly after addition, so it doesn’t remain active in the drink.
• Regulatory status: Authorized for specified uses and levels in the U.S. and the EU.
• Taste and texture: Used correctly, it has no lasting effect on flavor or mouthfeel.
• Labeling: In the EU it may appear as “E242” or “dimethyl dicarbonate.”

Why is Dimethyl dicarbonate added to food?

Manufacturers use dimethyl dicarbonate (DMDC) to control yeast and bacteria in beverages without heat. It is added during processing and then rapidly breaks down into methanol and carbon dioxide, so it does its job and then disappears as an active preservative.¹

What foods contain Dimethyl dicarbonate?

You’ll most often find DMDC in shelf-stable, ready-to-drink beverages such as flavored waters, iced teas, sports drinks, and juice-containing drinks. In the U.S., it’s allowed for use in certain nonalcoholic beverages, and it is also permitted in wine under alcohol rules.² In the European Union, E242 is authorized as a food additive in specific beverage categories listed in the EU additives regulation.³

What can replace Dimethyl dicarbonate?

Depending on the drink and process, common substitutes include:

• Heat treatments such as pasteurization
• Sterile filtration
• Other preservatives, for example potassium sorbate, sorbic acid, sodium benzoate, or, in wine, sulphur dioxide

How is Dimethyl dicarbonate made?

DMDC is produced by chemical synthesis and supplied as a high-purity liquid. In the EU, it must meet detailed identity and purity specifications set out for E242 in the additives specifications regulation.⁴

Is Dimethyl dicarbonate safe to eat?

Regulators allow DMDC only in certain foods and at specific maximum levels. In the U.S., the Food and Drug Administration (FDA) authorizes its use in beverages with conditions of use, noting that it rapidly hydrolyzes after addition.¹ In the EU, it is listed as E242 and may be used only in the beverage categories and amounts defined by law.³

Does Dimethyl dicarbonate have any benefits?

DMDC offers a “cold” way to control microbes, which can help beverages keep a fresh taste and avoid flavor changes from heat. Because it breaks down quickly, it does not continue preserving the drink, so good packaging and hygiene are still required.

Who should avoid Dimethyl dicarbonate?

Regulators have not singled out specific consumer groups that must avoid E242 at permitted use levels. People who prefer to avoid preservatives in general can choose products processed with heat or filtration instead.

Myths & facts

• Myth: “It stays in the drink.” Fact: DMDC works during processing and then breaks down quickly into simple substances.
• Myth: “It’s a long-term preservative like benzoates or sorbates.” Fact: It does not provide ongoing protection; the finished drink still relies on clean processing and proper packaging.
• Myth: “You can taste it.” Fact: When used correctly, it doesn’t leave a lasting taste because it hydrolyzes after doing its job.

Dimethyl dicarbonate in branded foods

You’re most likely to see E242 used in categories such as ready-to-drink teas, flavored waters, fruit-juice drinks, sports drinks, and some wines. In the EU, look for “dimethyl dicarbonate” or “E242” on the ingredient list when it is used as an additive.

References

Footnotes

1. Dimethyl dicarbonate — 21 CFR 172.133, U.S. FDA. https://www.ecfr.gov/current/title-21/part-172/section-172.133 ↩ ↩²

2. Materials authorized for the treatment of wine — 27 CFR 24.246, U.S. TTB. https://www.ecfr.gov/current/title-27/part-24/section-24.246 ↩

3. Food additives — Regulation (EC) No 1333/2008, European Union. https://eur-lex.europa.eu/eli/reg/2008/1333/oj ↩ ↩²

4. Specifications for food additives — Regulation (EU) No 231/2012, European Union. https://eur-lex.europa.eu/eli/reg/2012/231/oj ↩