Most additive advice asks you to take someone's word for it. This one is different: for six specific colours, the UK requires the warning to be printed on the pack. If you want a single additive rule worth acting on, it has already been written for you.
The six colours
Any food containing one of these must carry the wording “may have an adverse effect on activity and attention in children”:
| E number | Name | Colour |
|---|---|---|
| E102 | Tartrazine | yellow |
| E104 | Quinoline yellow | yellow |
| E110 | Sunset yellow FCF | orange-yellow |
| E122 | Carmoisine | red |
| E124 | Ponceau 4R | red |
| E129 | Allura red AC | red |
They are commonly called the Southampton Six, after the university whose research prompted the rule. The requirement itself sits in Annex V of Regulation (EC) No 1333/2008, retained in UK law after EU exit.
What the wording does and does not say
Read it carefully, because the regulator chose each word. It says may, it says activity and attention, and it says in children. It does not say the colours are unsafe, and it does not ban them — all six remain approved.
That combination tells you what the regulator concluded: the evidence was strong enough to warrant telling people, and not strong enough to justify withdrawal. Disclosure was the proportionate response. It is a genuinely unusual piece of food labelling, and it is more honest than most of what surrounds it.
In practice many manufacturers reformulated rather than print the sentence, which is why these colours are less common in UK products than the rules alone would predict. The warning worked mostly by making the colours commercially unattractive.
Colours and ultra-processed food
Separately from the warning, a colour is one of the most reliable signals that a product is ultra-processed. Under the NOVA classification, the test for a group 4 marker is whether an additive serves a cosmetic purpose — and a colour has no other purpose. It does not preserve, it does not stabilise, it does not make anything safer. It is there to be seen.
This is the cleanest case in the whole additive argument. Where citric acid is routinely mistaken for a marker and is not one, and emulsifiers genuinely divide expert coders, colours are unambiguous. If there is a colour on the label, you are holding a formulation.
What to do about it
If you are shopping for children, the warning is printed for you — no app required. More broadly, treat a colour as what it is: a reliable sign that the product was designed rather than cooked. That does not make it dangerous, and it is not a reason to panic about a birthday cake. It is information, which is all a label should be.
Cull names every colour it finds and flags it as a processing marker, rather than returning an additive count that treats a colour and a preservative as the same thing. Our additives guide explains the rest of the classes.
Sources
- Regulation (EC) No 1333/2008, Annex V — foods requiring additional labelling, including the six colours and the “activity and attention in children” wording
- UK Government / FSA — Food additives
- EFSA — Food additives: safety assessment and re-evaluation
- Monteiro et al. (2016) — NOVA. The star shines bright, World Nutrition