Carbon dioxide
A naturally occurring gas used to carbonate drinks, preserve packaged foods, and keep chilled products cold during transport.
What is it?
Carbon dioxide is a colourless, odourless gas that occurs naturally in the atmosphere, in the breath we exhale, and as a product of fermentation. For food use it is produced commercially, typically by capturing it from industrial processes such as ammonia production or fermentation, then purifying it to food-grade purity.
What does it do?
When dissolved under pressure in liquid, carbon dioxide forms carbonic acid, giving drinks their characteristic fizz and slight tartness. As a gas it displaces oxygen in sealed packaging, slowing the growth of aerobic bacteria and moulds. Solid carbon dioxide (dry ice) is used as a refrigerant. It also acts as a propellant in aerosol food products.
Where you will see it
Carbonated soft drinks, sparkling water, beer, cider, sparkling wine, and carbonated fruit juices are the primary uses. It is also used in modified-atmosphere packaging of fresh meat, fish, salads, and bakery goods to extend shelf life, and as a chilling agent in chilled and frozen food transport. On a UK ingredient label it appears as 'carbon dioxide' or 'E290'.
What the science says
Carbonation and tooth enamel
Carbonated drinks are mildly acidic because dissolved carbon dioxide forms carbonic acid. Frequent consumption of carbonated drinks is associated with dental erosion, but research points to the added sugars and citric or phosphoric acids as the main drivers rather than carbonic acid alone. Plain sparkling water has a very low erosion potential compared with cola or fruit-carbonated drinks.
Sparkling water showed minimal erosive potential compared with acidic carbonated soft drinks; the erosive effect of carbonated beverages is attributed mainly to added organic acids, not carbonic acid itself.
Digestive effects of carbonation
Swallowed carbon dioxide gas contributes to belching and bloating in some people. For most people this is transient. Those with irritable bowel syndrome or functional dyspepsia may find carbonated drinks worsen symptoms; clinical guidance typically advises they reduce carbonated drink intake.
In people with functional gastrointestinal disorders, carbonated beverages can exacerbate bloating and abdominal discomfort; standard dietary advice in these populations includes limiting carbonated drinks.
Regulatory safety review
European and UK food safety bodies have not set a numerical acceptable daily intake for carbon dioxide used in food, because the gas is a normal metabolic product of the human body and the amounts ingested from food are negligible compared with the body's own production. No data gaps or safety concerns have been flagged.
EFSA concluded that carbon dioxide used as a food additive raises no safety concern at currently permitted levels, and no numerical ADI is required.
Where it stands with the regulators
Who should be careful
People with irritable bowel syndrome or functional dyspepsia are often advised by dietitians to reduce carbonated drink intake, as the gas can worsen bloating and discomfort. Look for 'carbon dioxide' or 'E290' on ingredient lists, but note that carbonation itself is usually implied by 'sparkling' or 'carbonated' on the front of the pack.
The honest read
Carbon dioxide is one of the most ordinary substances used in food processing. It is the same gas produced when yeast ferments sugar to make bread rise or beer ferment, and the same gas exhaled with every breath. The minor effects, tooth acid exposure from carbonated soft drinks and gas-related bloating, come almost entirely from the other ingredients in carbonated products or from the physical effect of dissolved gas, not from the molecule itself acting as a food chemical. There is no ongoing scientific debate about E290 as a food additive.
Related additives
Common questions
Is E290 banned in the UK?
No. Carbon dioxide is fully approved for use in food and drinks in the UK under the UK FSA approved-additives list and retained EU Regulation 1333/2008.
Can carbonated drinks damage your teeth?
Carbonated soft drinks, colas, and fruit-flavoured fizzy drinks are associated with dental erosion, but research indicates the main culprits are added citric acid, phosphoric acid, and sugar rather than carbonic acid from the carbon dioxide itself. Plain sparkling water has a low erosion risk.
What foods contain E290?
Carbonated soft drinks, sparkling water, beer, cider, sparkling wine, and carbonated fruit juices all use it for fizz. It also appears in modified-atmosphere packaging on fresh meat, fish, salads, and some bakery products to extend shelf life, though it is not always listed when used purely as a packaging gas.
Is E290 vegan?
Yes. Carbon dioxide is a gas with no animal-derived components. It is suitable for vegans and vegetarians.
Sources
- UK FSA Approved Additives and E Numbers
- EFSA re-evaluation of carbon dioxide (E 290) as a food additive
- EU Regulation 1333/2008 on food additives (Annex II)
- Cheng R et al., Dental erosion and severe tooth decay related to soft drinks, British Dental Journal
- Olesen SS, Madsen G. Carbonated beverages and gastrointestinal symptoms, European Journal of Gastroenterology and Hepatology
See this on every food you scan
NutraSafe reads the label and puts every additive into plain English, with the source, right in the app.
Get NutraSafe on the App Store