The food dyes that carry a legal warning label
Six synthetic dyes must carry the warning "may have an adverse effect on activity and attention in children" on EU labels, following the 2007 Southampton study.
The six dyes
| E-number | Name | Colour |
|---|---|---|
| E102 | Tartrazine | Yellow |
| E104 | Quinoline yellow | Yellow |
| E110 | Sunset yellow FCF | Orange-yellow |
| E122 | Carmoisine (azorubine) | Red |
| E124 | Ponceau 4R | Red |
| E129 | Allura red AC | Red |
They are collectively known as the "Southampton Six", after the study that produced the warning requirement.
What the study found
A 2007 study at the University of Southampton, published in The Lancet, tested mixtures of these dyes plus the preservative sodium benzoate (E211) on children aged three and eight or nine. It reported increased hyperactivity in the general child population, not only in children already diagnosed with ADHD.
The findings were debated. EFSA reviewed the study and considered the evidence insufficient to change the acceptable daily intakes. The European Parliament nonetheless legislated a mandatory warning, which is an unusual and instructive outcome: the regulator did not accept the safety case for a change, and the legislature required disclosure anyway.
The result is the sentence now printed on packets across the EU:
"May have an adverse effect on activity and attention in children."
Why this matters more than an app score
Most food-scanning apps assign additives a risk grade. Those grades are judgement calls made by whoever built the app, using weightings you cannot inspect.
This warning is different in kind. It is a legal requirement, printed by the manufacturer, mandated by legislators. Whatever you conclude about the underlying science, it is the single most authoritative additive signal available on a European food label, and it is one of the few places where the packet itself is telling you something rather than selling you something.
The industry response
Manufacturers largely did not print the warning. They reformulated.
Faced with a choice between a warning label and switching to natural colourings, most major brands in the EU switched. Beetroot red (E162), anthocyanins (E163), paprika extract (E160c), curcumin (E100) and spirulina extract replaced the azo dyes across much of the market.
This is why the same brand's product can look visibly different in the EU and the US: reformulated in one market, left alone in the other. Photographs comparing EU and US versions of the same sweets circulate regularly, and they are generally accurate.
Where you will still find them
- Imported sweets and drinks, particularly from outside the EU
- Very cheap confectionery, where reformulation cost matters more
- Some medications and supplements, where colouring rules differ
- Products from markets without the warning requirement
The other red to know about
E120 carmine is not in the Southampton Six and carries no warning. It is a natural, insect-derived red. Its issue is not attention. It is that it is made from crushed insects, which matters for vegan, vegetarian, halal and kosher diets, and it is a documented allergen for a small number of people.
Two different problems, both under "red colouring", requiring two different responses.
Checking a product
The warning is legally required to be on the pack, so it is readable, but on an imported product with a sticker-applied translation, or in tiny type at the end of a long ingredient list, it is easy to miss.
Scanning returns every colour in the product by name and E-number, which makes the Southampton Six visible at a glance rather than something you have to hunt for.
Frequently asked
Which food colours are banned in Europe?
Few are outright banned; the Southampton Six are permitted but require a warning that they may affect activity and attention in children. E171 titanium dioxide, a whitener rather than a colour, was removed from the EU permitted list in 2022 and remains legal in the US.
Why do the same sweets look different in the US and EU?
Because most EU manufacturers reformulated with natural colourings rather than print the mandatory child-attention warning. The US has no equivalent requirement, so US versions frequently retain the synthetic azo dyes.