Plain caramel
Brown colour made by heating sugar without chemicals. Used in cola, beer, whisky, sauces and baked goods.
A large observational study found people with higher intake were 15% more likely to develop cancer overall. The finding survived statistical correction, but the study is observational and cannot prove cause.
What is it?
Plain caramel (Class I caramel colour) is produced by heating carbohydrates such as sucrose, glucose or fructose without ammonia or sulphite compounds. It is the simplest of the four caramel colour classes and is the same type of browning that occurs naturally during home cooking. It forms as a dark brown liquid or solid with a slightly bitter taste.
What does it do?
It absorbs light across a wide spectrum to produce golden to dark brown colours. Producers use it to standardise the appearance of batches of food or drink that would otherwise vary in colour, and to signal qualities such as maturity or roasting.
Where you will see it
Cola drinks, stout and dark beers, Scotch whisky and other spirits (where it can be added to even out colour between casks), malt vinegar, brown bread, soy sauce, gravy, biscuits, cookies, soups, pet food. On a UK label it appears as 'caramel colour', 'E150a' or 'plain caramel'. Spirits do not require a full ingredients list under UK law, so E150a in whisky may not be declared.
What the science says
Observational cancer association
A large French cohort study followed over 105,000 adults for more than seven years and found that people with higher intake of E150a had a 15% higher hazard ratio for overall cancer (HR 1.15, 95% CI 1.07-1.25). This association remained after controlling for smoking, alcohol, diet quality and other confounders, and after a false discovery rate correction for the many additives tested. The study is observational: it records what people happened to eat, so it cannot rule out that something else in the diets of high caramel consumers explains the finding. No specific cancer type was identified as the driver for E150a specifically.
In a prospective cohort of 105,260 adults, higher E150a intake was associated with increased overall cancer incidence (HR 1.15, 95% CI 1.07-1.25) after false discovery rate correction, with absolute risks of 14.0% in higher consumers versus 12.1% in lower or non-consumers.
Genotoxicity and carcinogenicity tests
EFSA's 2011 full re-evaluation of all four caramel colour classes concluded that E150a is not genotoxic and not carcinogenic, and that there is no evidence of adverse effects on human reproduction or child development. E150a does not contain 4-methylimidazole (4-MEI), the compound linked to tumours in rodents at very high doses in ammonia-containing caramel classes (E150c and E150d), because its production uses no ammonia.
EFSA ANS Panel concluded caramel colours, including E150a, are neither genotoxic nor carcinogenic and show no evidence of adverse reproductive or developmental effects.
E150a (Class I plain caramel) does not use ammonia in production and therefore does not produce 4-methylimidazole, the by-product that drove cancer concerns for ammonia-containing caramel classes.
Acceptable daily intake and exposure
JECFA (the WHO/FAO expert committee) historically assigned E150a an ADI of 'not specified', meaning it did not consider a numerical limit necessary given how closely the additive resembles natural cooking chemistry. The EFSA 2011 re-evaluation set a group ADI of 300mg/kg body weight per day covering all four caramel colour classes together. A 2012 refined exposure assessment, using actual product use levels from industry, found that real-world exposure for all population groups falls below that group ADI.
JECFA (29th meeting, 1985) assigned E150a an ADI of 'not specified', determining that a numerical limit was not necessary because its production closely resembles natural cooking processes.
EFSA established a group ADI of 300mg/kg body weight per day for all four caramel colour classes, and a 2012 refined assessment found that anticipated dietary exposure to E150a is below this ADI for all population groups at both mean and high exposure levels.
5-Hydroxymethylfurfural as a processing by-product
Heating sugars to make caramel colour produces small amounts of 5-hydroxymethylfurfural (5-HMF), a compound also found in many cooked and processed foods. In vitro tests with high concentrations have produced DNA damage signals through a reactive metabolite, but in vivo tests in living animals have consistently been negative for genotoxicity. Animal studies suggest toxic effects only at doses far above any realistic dietary exposure from caramel colour. EFSA flagged in 2011 that 5-HMF exposure from caramel colours warranted further evaluation, and production optimisation can reduce its levels.
5-HMF demonstrated genotoxic activity through its reactive metabolite in some in vitro tests, but did not form micronuclei in the in vivo mouse micronucleus assay, indicating the mechanism may not operate in living organisms.
Animal studies identified toxic effects of 5-HMF only at doses above 75mg/kg body weight per day, well above estimated human dietary exposure from caramel colour-containing foods.
Where it stands with the regulators
Who should be careful
People with wheat or barley allergies should note that some E150a is produced from glucose syrup derived from wheat or malt. Although these are exempt from allergen labelling under EU/UK Regulation 1169/2011 because the protein is removed during processing, those with severe grain allergies may want to check with manufacturers. Spirits such as whisky may contain E150a without declaring it on the label; if this matters to you, look for bottles labelled 'natural colour only' or 'no added colour'.
The honest read
E150a is one of the oldest and most studied food colours, produced by the same basic chemistry as home caramelisation. Regulators in the UK, EU, US and internationally have reviewed it repeatedly and found no genotoxicity or carcinogenicity in formal testing. Unlike ammonia-based caramel colours (E150c and E150d), it produces no 4-MEI by-product. The 2026 NutriNet-Sante cohort study is the first to find a statistically significant association between E150a specifically and overall cancer in humans; the finding is notable because it survived a rigorous false discovery rate correction across many additives. However, it remains a single observational study and the researchers acknowledge residual confounding, reverse causation and selection bias as limitations. This association has not previously been detected in regulatory testing programmes, and no causal mechanism has been established. The science has moved, but it has not settled.
Related additives
Common questions
Is E150a banned in the UK?
No. E150a is approved for use in the UK under the assimilated EU Regulation 1333/2008 and is listed on the UK FSA approved-additives register. It is permitted at quantum satis (no fixed maximum level) in a wide range of foods.
Is E150a the same as the caramel colour linked to cancer concerns?
Cancer concerns in earlier years focused mainly on E150c and E150d, which are produced using ammonia and can contain 4-methylimidazole (4-MEI), a compound linked to rodent tumours at very high doses. E150a does not use ammonia and does not produce 4-MEI. A 2026 observational cohort study found a 15% higher cancer hazard ratio for higher E150a consumers, but the study cannot prove causation and formal toxicology tests have not found a carcinogenic mechanism for E150a.
What foods contain E150a?
Cola drinks, dark beers and stouts, malt vinegar, gravy and brown sauces, Scotch whisky and many blended spirits, brown bread, biscuits, cookies, soups and some confectionery. On UK labels it appears as 'caramel colour', 'plain caramel' or 'E150a'. Spirits do not require a full ingredients list, so caramel colouring in whisky may go undeclared.
Is E150a vegan?
Usually, but not always. E150a is made from plant-derived sugars such as cane sugar, beet sugar, corn syrup or wheat glucose syrup. If cane sugar is used, it may have been refined through bone char from animal bones, which some strict vegans avoid. Check with individual manufacturers if this matters to you.
Sources
- UK FSA Regulated Products Database - E150a Plain caramel
- UK FSA Approved Additives and E Numbers
- EFSA ANS Panel: Scientific Opinion on re-evaluation of caramel colours (E150a,b,c,d) as food additives, EFSA Journal 2011;9(3):2004
- EFSA Journal: Refined exposure assessment for caramel colours (E150a,c,d), 2012;10(12):3030
- JECFA food additives database - Caramel Colour Class I (Chemical 423)
- NutriNet-Sante: Food colouring additives and cancer incidence - European Journal of Epidemiology, 2026
- Toxicological aspects of heat-borne toxicant 5-hydroxymethylfurfural in animals: A Review, PMC7221839
- Abraham et al., Toxicology and risk assessment of 5-HMF in food, Molecular Nutrition and Food Research, 2011
- Commission Regulation (EU) No 505/2014 on caramel colours in beer and malt beverages
- Whiskipedia: Spirit caramel (E150a) in whisky
- Wikipedia: Caramel color
Aaron Keen is the founder of NutraSafe. He researches and writes every additive entry himself, from the primary sources. About the research →
This is a guide, not medical advice. If an additive affects you, speak to your GP or a dietitian.
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