Sunset Yellow (E110): The Orange Dye Linked to Hives

Sunset Yellow (E110) is a synthetic orange azo dye in drinks and sweets, and one of the colours linked to hives and itching in sensitive people. What it is, who reacts, and how to spot it.

What it is

Sunset Yellow is a synthetic azo dye that gives food and drink a bright orange-yellow colour. On labels it appears as Sunset Yellow, Sunset Yellow FCF, E110, or in the United States as FD&C Yellow 6. It is cheap, stable and vivid, which is why it turns up in so many soft drinks, sweets and snacks. It is one of the “Southampton Six” colours studied for effects on children’s behaviour, the research that led many UK brands to drop artificial colours.

Who reacts, and how it shows on the skin

For most people Sunset Yellow causes no problem. In a sensitive minority it is one of the azo colours linked to hives (urticaria), itching and flushing, and to a worsening of long-standing skin conditions, sometimes hours after eating rather than straight away. People who already have chronic hives, or who are sensitive to aspirin and other salicylates, are more likely to notice a reaction. This is usually a pseudo-allergic response rather than a true food allergy, so standard allergy tests often come back normal even when the skin clearly reacts.

Where it hides

Orange and citrus-flavoured squashes and fizzy drinks, sweets, ice lollies, snack foods, packet sauces and desserts, apricot jam, and some medicines and supplements. On the label look for Sunset Yellow, E110, FCF or Yellow 6. In the UK and EU, foods containing it must also carry the warning “may have an adverse effect on activity and attention in children”.

What to do if you think you react

Note what you ate or drank and when your skin flared, and look for a pattern over a couple of weeks before cutting things out. Because azo dyes cross over, if you react to one it is worth screening for the others. Many UK brands now colour with fruit and vegetable extracts, so naturally-coloured swaps make a good test. If reactions are frequent or severe, see a GP or allergist.

Check it against your own list

A free scanner like Yuka gives a packaged product a general health score, a useful broad read, though that verdict is the same for everyone rather than tuned to your skin. Fig is genuinely good if you are managing a defined eating pattern. To check a product against the specific things that make your skin react, a personal-list app like ClearaScan lets you save your triggers once and scan any product, food, medication or cosmetic, against your ingredient guard list, flagging only yours. Its Reaction Journal lets you tie a flare back to the product that caused it, a shared Care Circle lets family scan for you, and a Trusted Products list keeps what you have cleared. It is currently in early access. (Disclosure: our editor co-founded ClearaScan, and we are not paid to mention the others.)