What is it?
Sunset Yellow FCF, also called Orange Yellow S, is a man-made orange-yellow dye made from petroleum-based chemicals. It is an azo dye, the family that includes the other Southampton Six colours.
Sunset Yellow
also: FD&C Yellow No. 6 · Yellow 6 · Orange Yellow S · CI 15985
A synthetic orange azo dye from petroleum, added to food and drinks to give a yellow-to-orange colour.
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Carbonated Water, Sugar, Acid (Citric Acid), Flavourings (including Ammonium Ferric Citrate & Quinine), Preservative (E211), Foaming Agent (Quillaia Extract), Colours (Sunset Yellow FCF, Ponceau 4R)
E110
Sunset Yellow
One of the Southampton Six colours.
VeganVegetarianHalalKosher
75
of the 43,325 UK supermarket foods we checked declare E110 in their ingredients
That is 0.2%, counted by its code or its name.
Only 33% of these labels print “E110”. Most use the name: look for “sunset yellow fcf”.
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 juices43 products1.6% of 2,627
- Fruit, vegetables and salad13 products0.5% of 2,631
- Cupboard staples5 products0.3% of 1,936
What Sunset Yellow is, what it does and where you will see it
Why it’s worth knowing. One of the Southampton Six colours. A 2007 UK trial found children were more hyperactive after drinks containing it mixed with other colours. Any UK food or drink containing it must say it "may have an adverse effect on activity and attention in children". Some people who react to aspirin, or who get hives, report skin reactions to it.
What does it do?
It colours food and drink orange or yellow. That is all it does: it adds no flavour, texture or nutrition. It holds its colour through heat and most food processing.
Where you will see it
Orange and lemon squashes, fizzy drinks (Irn-Bru among them), sweets, mustard, sauces and pickles, marzipan, desserts, fish roe and smoked salmon substitutes, and some food supplements. Labels call it Sunset Yellow FCF, Orange Yellow S or E110.
What the science says
Linked to more hyperactivity in children when mixed with other colours
In a 2007 UK trial, children aged 3 and 8 to 9 drank either a drink with six artificial colours, including E110, plus the preservative sodium benzoate, or a dummy drink. They were measurably more hyperactive after the coloured drinks. European reviewers agreed there was a small effect in some children, but said it was not consistent across the two age groups or the two mixtures. Later reviews of many trials found the effect is modest, bigger in parents' ratings than teachers', and too small to use cutting out colours as a treatment for ADHD on its own.
Children aged 3 and 8 to 9 who drank a mixture of artificial colours including E110, plus sodium benzoate, were more hyperactive than when they drank a dummy drink. Neither the children nor the researchers knew which drink was which.
2007Randomised trial in peopleMcCann et al., The Lancet
European reviewers said the Southampton study gave limited evidence of a small effect on activity and attention in some children, but the results were not consistent across age groups or the two colour mixtures.
2008Regulator reviewEFSA Panel on Food Additives, Flavourings, Processing Aids and Food Contact Materials (AFC), EFSA Journal
Across trials where colours were cut out, the effect on hyperactivity measured 0.21 to 0.44 in parents' ratings but only 0.08 to 0.11 in teachers' and observers' ratings. The authors judged it too small to recommend as a general ADHD treatment.
2017Review of many trialsNigg et al., PLOS ONE / Journal of Child Psychology and Psychiatry, systematic review
UK law requires a hyperactivity warning on the pack
Since 20 July 2010 any food or drink containing E110 must say it "may have an adverse effect on activity and attention in children". The rule came from EU law and stayed in UK law after Brexit. It is a legal requirement, not advice. The Food Standards Agency asked makers to stop using it in 2008, and many UK brands did, but it is still allowed.
Any food or drink containing E110 must carry the warning "may have an adverse effect on activity and attention in children". The rule has applied since July 2010 and is kept in UK law.
2010LawEU Regulation 1333/2008 on food additives, Article 24; UK FSA
After reviewing the Southampton study, the Food Standards Agency asked UK makers in 2008 to phase out the six colours, E110 among them, by the end of 2009. It was a request, not a ban.
2008Regulator adviceUK Food Standards Agency
Can cause skin reactions in people sensitive to aspirin
As an azo dye, E110 can set off reactions that look like allergy, such as hives and swelling, in people who react to aspirin or salicylates or who have long-term hives. European reviewers said these reactions have been reported but are uncommon. In a trial of people with long-term hives, far fewer reacted to azo dyes when tested than said they did.
Reviewers found that reactions to Sunset Yellow FCF, including hives and swelling, have been reported in sensitive people, but that it is unlikely to cause serious reactions in the general population at permitted levels.
2010Regulator reviewEFSA ANS Panel, EFSA Journal 8(10):1778
Of 39 people with long-term hives given a capsule of six azo dyes including E110, only 2 (5.1%) reacted, with a dummy capsule for comparison. Confirmed reactions were much rarer than people's own reports suggested.
2022Trial in peopleHypersensitivity of azo dyes in urticaria patients study, PMC9704453
A cut in the daily limit over rat studies, later reversed
In 2009 European reviewers cut the daily limit from 2.5 to 1mg per kg of body weight, after rat studies reported effects on the testes and sperm at high doses. The dye in those studies came from a local market and its purity was unknown. Longer studies using pure dye did not repeat the effect, and in 2014 the limit was raised to 4mg per kg.
Reviewers set a temporary lower limit of 1mg per kg of body weight a day in 2009, after rat studies reported effects on the testes at 250mg per kg a day and above. The purity of the dye tested was not confirmed.
2009Regulator reviewEFSA ANS Panel, Scientific Opinion on re-evaluation of Sunset Yellow FCF (E110), EFSA Journal 7(11):1330
After new studies using dye of certified purity, reviewers found no DNA damage concern and no consistent effect on the testes. They set the limit at 4mg per kg a day, from the highest dose with no effect in a long-term rat study, 375mg per kg.
2014Regulator reviewEFSA ANS Panel, Reconsideration of the temporary ADI for Sunset Yellow FCF (E110), EFSA Journal 12(7):3765
Liver and kidney changes in rats given the dye on its own
Some rat studies have found signs of stress on cells and changes to liver and kidney tissue in rats given E110 every day. One lab study found gut bacteria in treated animals may turn it into something weakly damaging to DNA. Other tests in mice found no DNA damage. These were animals given the dye on its own, so they do not tell us directly what it does in food at permitted levels.
Male rats given Sunset Yellow at 2.5mg per kg of body weight a day for four weeks had raised liver enzymes and kidney markers, signs of stress on cells, and changes to liver and kidney tissue.
2018Animal studyAhmed et al., Toxicology Reports / PMC6166620
A test in living mice found no DNA damage from Sunset Yellow FCF at doses up to 2000mg per kg of body weight.
2022Animal studyAkhaltseva et al., Hygiene and Sanitation journal
Extracts from the urine, bile and bone marrow of treated rodents did not damage DNA in a bacterial test. Extracts from their faeces did, weakly, when an extra step mimicking metabolism was added, suggesting gut bacteria may turn E110 into weakly harmful substances.
1989Lab and animal studyWever et al., Environmental and Molecular Mutagenesis
Where it stands with the regulators
Approved in the UK and the EU, with a warning label
Daily limit. 4mg per kg of body weight a day, about 280mg for a 70kg adult (European reviewers 2014, international committee 2011).
- Legal basis
- On the Food Standards Agency's approved list, with the purity rules the UK kept from EU law
- Permitted foods
- Flavoured yoghurts and fermented milks · Flavoured creams · Sweets other than chocolate · Sugar-coated sweets · Chewing gum · Cake decorations, coatings, sauces and fillings · Batters · Mustard · Pickles and piccalilli · Fish roe and salmon substitutes · Vegetable protein products · Flavoured drinks · Cider and perry · Fruit wine and made wine · Flavoured wines and wine-based drinks · Alcoholic drinks under 15% alcohol · Desserts · Food supplements · Candied fruit and vegetables · Foods for special medical needs and weight control
- Maximum levels
- Depends on the food: 5mg per kg in flavoured dairy and desserts, 10 to 50mg per kg in sweets and mustard, up to 200mg per kg in fish roe and salmon substitutes, 20mg per litre in flavoured drinks.
- History
- The international committee first set a limit of 2.5mg per kg in the 1970s. In 2009, after the Southampton study and rat studies suggesting effects on the testes, European reviewers cut it to 1mg. When newer studies with pure dye did not repeat the testes finding, they set it at 4mg in 2014. Since 20 July 2010 UK and EU law have required any food containing E110 to carry the warning "may have an adverse effect on activity and attention in children". The Food Standards Agency asked makers to phase it out in 2008. Many UK brands did, but it is still allowed. Limits in soft drinks were lowered in 2012.
Who should be careful
Parents who want to cut down on the Southampton Six colours, given the warning the law requires. People who react to aspirin or salicylates, or who have long-term hives or swelling, because azo dyes can set off reactions that look like allergy. Look for Sunset Yellow FCF, Orange Yellow S or E110 in the ingredients, and for the warning "may have an adverse effect on activity and attention in children". More on the Southampton Six.
The honest read
The hyperactivity finding is the main reason people know E110. The 2007 trial was well designed and paid for by the government, which is why it led to the UK warning label. But the effect it found was modest, it was not the same in both age groups or both colour mixtures, and later reviews found it too small to treat ADHD by cutting colours out.
What is settled: the warning label is the law, and the Food Standards Agency asked makers to drop the dye. What is not settled: whether the effect matters for an individual child eating an ordinary diet, and whether any one colour in the mixture is behind it. The 2009 scare over rat testes was reversed in 2014 when better studies did not repeat it. Rat studies still find signs of stress on liver and kidney cells, but nobody has shown what that means for people at permitted amounts. There is also a real but uncommon risk for people who react to aspirin.
Common questions about Sunset Yellow
Is E110 banned in the UK?
No. It is an approved additive in the UK. Since July 2010 any product containing it must carry the warning "may have an adverse effect on activity and attention in children". The Food Standards Agency asked makers to remove it in 2008, and many UK brands did, but it is still allowed.
Why does E110 have a warning label?
Because of a 2007 University of Southampton study, paid for by the Food Standards Agency. Children who drank a mix of six artificial colours, including E110, with the preservative sodium benzoate were more hyperactive than when they drank a dummy drink. The warning became law on 20 July 2010 and applies to any product containing any of the six colours.
Is E110 harmful?
It is approved, with a daily limit of 4mg per kg of body weight and a legal hyperactivity warning. The trial behind the warning found a modest effect in some children when it was mixed with other colours. It can set off reactions such as hives in people sensitive to aspirin. Rat studies found liver and kidney changes, but what that means for people at permitted amounts has not been shown.
What foods contain E110?
Fizzy drinks (Irn-Bru among them), orange and lemon squashes, sweets, mustard, sauces and pickles, smoked salmon substitutes and fish roe, some desserts and marzipan. Many UK brands took it out after 2008, but it is still in some products, especially imported sweets and some soft drinks. Check the ingredients for Sunset Yellow FCF, Orange Yellow S or E110.
Is E110 vegan?
It is made from petroleum-based chemicals and contains no animal ingredients, so most vegans accept it. Some avoid it because artificial food dyes are still tested on animals as part of safety checks.
Sources
- UK FSA: Approved additives and E numbers - E110 Sunset Yellow FCF
- UK FSA Regulated Products Register: E110
- UK FSA: Food additives (Southampton Six and warning labels)
- McCann et al. - Food additives and hyperactive behaviour in 3-year-old and 8/9-year-old children: a randomised, double-blinded, placebo-controlled trial. The Lancet.
- EFSA AFC Panel - Assessment of McCann et al. 2007 Southampton study. EFSA Journal.
- EFSA ANS Panel - Scientific Opinion on re-evaluation of Sunset Yellow FCF (E110) as a food additive. EFSA Journal 7(11):1330.
- EFSA ANS Panel - Reconsideration of the temporary ADI and refined exposure assessment for Sunset Yellow FCF (E110). EFSA Journal 12(7):3765.
- EFSA ANS Panel - Scientific Opinion on appropriateness of food azo-colours for inclusion in allergen labelling list. EFSA Journal 8(10):1778.
- Commission Regulation (EU) No 232/2012 amending Annex II to Regulation (EC) No 1333/2008 regarding conditions of use for E110
- Nigg et al. - Diet and ADHD, Reviewing the Evidence: A Systematic Review of Meta-Analyses of Double-Blind Placebo-Controlled Trials. PLOS ONE.
- Ahmed et al. - Sunset Yellow and Allura Red modulate Bcl2 and COX2 expression levels and confer oxidative stress-mediated renal and hepatic toxicity in male rats. Toxicology Reports.
- Hypersensitivity of azo dyes in urticaria patients based on a single-blind, placebo-controlled oral challenge. PMC9704453.
- Akhaltseva et al. - Evaluation of the genotoxicity of the food dye Sunset Yellow FCF in a micronucleus test in vivo. Hygiene and Sanitation.
- Wever et al. - Testing of sunset yellow and orange II for genotoxicity in different laboratory animal species. Environmental and Molecular Mutagenesis.
Last reviewed: 20 June 2026
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