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.
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)
One of the Southampton Six colours.
UK supermarket foods that declare E110: 75 of the 43,325 we checked (0.2%)
Counted by its code or its name in the ingredient list.
Counted by NutraSafe from UK supermarket ingredient lists, September 2026. How we counted
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.
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.
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.
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.
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.
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.
European reviewers said the Southampton study gave limited evidence of a small effect on activity and attention in some children.
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.
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.
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.
Reviewers noted that reactions to Sunset Yellow FCF, including hives and swelling, have been reported in sensitive people.
Of 39 people with long-term hives given a capsule of six azo dyes including E110, 2 (5.1%) reacted, with a dummy capsule for comparison.
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. 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.
Reviewers 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.
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.
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.
A test in living mice found no DNA damage from Sunset Yellow FCF at doses up to 2000mg per kg of body weight.
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.
In April 2025 the US Food and Drug Administration said it would work with food makers to remove six petroleum-based dyes from American food by the end of 2026. E110 is one of them, sold there as Yellow No. 6. The agency asked companies to take the dyes out rather than withdrawing their approval. It does not change the rules in the UK, where E110 is still allowed with its warning label.
The FDA said it would work with industry to eliminate six synthetic dyes from the US food supply by the end of 2026, Yellow No. 6 and Yellow No. 5 among them, and asked companies to remove them sooner where they can.
Daily limit. 4mg per kg of body weight a day, about 280mg for a 70kg adult (European reviewers 2014, international committee 2011).
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 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.
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 any one colour in the mixture is behind it. Rat studies still find signs of stress on liver and kidney cells. There is also a real but uncommon risk for people who react to aspirin.
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.
No. It is allowed in the UK, but the Food Standards Agency asked makers to phase it out voluntarily. In April 2025 the US Food and Drug Administration asked food makers to remove Yellow No. 6, its US name, and five other petroleum-based dyes from American food by the end of 2026, rather than withdrawing their approval.
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.
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.
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.
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.
Last reviewed: 9 November 2026
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