The Southampton Six: Which Food Additives May Affect Children?

What is the Southampton Study?

In 2007, researchers at the University of Southampton published a study in The Lancet (McCann et al.) that tested the effects of two different mixes of artificial food colourings and the preservative sodium benzoate on children's behaviour. It was funded by the UK Food Standards Agency (FSA) and is one of the most widely cited pieces of research on food additives and children.

The study tested two age groups — 3-year-olds (137 children) and 8-to-9-year-olds (130 children) — using a double-blind, placebo-controlled design. This means neither the children, their parents, nor the researchers knew which drink each child received on any given day.

Each child was given three different drinks over separate weeks:

• Mix A — a cocktail of four colourings (Sunset Yellow, Carmoisine, Tartrazine, Ponceau 4R) plus sodium benzoate
• Mix B — a cocktail of four colourings (Sunset Yellow, Carmoisine, Quinoline Yellow, Allura Red) plus sodium benzoate
• Placebo — a drink that looked and tasted similar but contained no colourings or preservatives

The key finding: children who consumed Mix A or Mix B showed statistically significant increases in hyperactive behaviour compared to the placebo. The effect was observed in both age groups, though results varied between the mixes and the ages.

The six colourings (and the preservative)

The term "Southampton Six" refers to the six artificial food colourings used across the two test mixes. There is also a seventh additive — sodium benzoate — which appeared in both mixes but is a preservative rather than a colouring.

*Sodium benzoate was in both test mixes but is not formally one of the "six" colourings. Because it appeared in every active test drink, the study could not determine its individual contribution to the results.

What happened after the study

The FSA response

The UK Food Standards Agency reviewed the Southampton findings and took a measured approach. Rather than banning the colourings outright, the FSA:

• Advised parents that if their child showed signs of hyperactivity or attention problems, removing these colourings from their diet might help
• Asked UK food manufacturers to voluntarily remove the Southampton Six from their products and find natural alternatives
• Referred the evidence to the European Food Safety Authority (EFSA) for a formal risk assessment

Most major UK manufacturers responded. Brands like Smarties, Ribena, and many supermarket own-label products reformulated to replace artificial colourings with natural alternatives (such as beetroot extract, paprika, and spirulina).

EU regulation

In 2010, the European Parliament adopted a regulation (EU Regulation 1333/2008, with labelling provisions under Regulation 1129/2011) requiring any food containing one or more of the Southampton Six colourings to carry the warning:

This warning applies across the UK (retained in domestic law post-Brexit) and the EU. It does not apply to sodium benzoate (E211), only to the six colourings.

Limitations of the study

The Southampton study is important, but it has limitations that are worth understanding. Being aware of these helps put the findings in proper context:

• Mixed additives — Each test drink contained multiple colourings plus sodium benzoate. The study cannot tell us which specific additive (or combination) caused the effect. It is possible that one colouring drives most of the response, or that the combination is what matters.
• Modest effect sizes — While statistically significant, the increase in hyperactivity was relatively small at a population level. Not every child showed a response, and some children appeared unaffected.
• Artificial dosing — The amounts of colourings in the test drinks were designed to represent typical daily intake, but real-world consumption patterns vary widely. A child eating a single coloured sweet would consume far less than the test dose.
• No individual additive testing — Because mixes were used, we cannot say "E129 causes hyperactivity" in isolation. The study shows an effect of the mixtures as a whole.
• Behaviour measurement challenges — Hyperactivity was assessed partly through subjective parent and teacher ratings, which can be influenced by expectations and daily variation.

The EFSA panel, reviewing the study in 2008, concluded that while the findings provided "limited evidence" of an effect, the data did not warrant changing the Acceptable Daily Intake (ADI) for any of the individual colourings. However, the EU still implemented the warning label requirement as a precautionary measure.

Where do things stand now?

Nearly two decades on from the Southampton study, here is the current situation in the UK:

• Most major UK brands have removed the Southampton Six from their products. If you shop at Tesco, Sainsbury's, Asda, or Morrisons, the majority of own-brand products no longer contain them.
• They still appear in some products, particularly cheaper confectionery, imported sweets and snacks, some cake decorations, and certain budget soft drinks. Some children's medicines also use these colourings.
• The warning label is mandatory on any product sold in the UK that contains one or more of the six colourings.
• Natural alternatives are widely available. Manufacturers have successfully replaced most artificial colourings with plant-based alternatives that achieve similar visual results.

How to check for the Southampton Six

Spotting these additives is straightforward once you know what to look for:

1. Read the ingredients list. Look for the E-numbers (E102, E104, E110, E122, E124, E129) or their common names (Tartrazine, Quinoline Yellow, Sunset Yellow, Carmoisine, Ponceau 4R, Allura Red).
2. Look for the warning label. Any product containing these must display the "may have an adverse effect on activity and attention in children" warning.
3. Use a food additive scanner app. Scanning the barcode gives you an instant breakdown of all additives in the product, including whether any of the Southampton Six are present.

For a full guide to understanding E-numbers on UK food labels, including which ones are considered safe and which have restrictions, see our complete guide to E-numbers.

Should you avoid these colourings?

This is a personal decision, and the evidence supports a measured approach rather than alarm:

• If your child shows signs of hyperactivity or attention difficulties, removing these colourings from their diet is a reasonable step to try. The FSA suggests this as one option, alongside speaking to a GP or health visitor.
• If your child has no behavioural concerns, the risk from occasional exposure to these colourings is considered very low by both the FSA and EFSA. The amounts found in most products are small.
• You may want to avoid them on general principle. Many parents prefer to minimise artificial additives in their children's diets, which is a valid choice. The good news is that most UK products have already made this easy by switching to natural alternatives.

The important thing is to not panic. These colourings are not poisons. They passed safety assessments and are legally permitted. The Southampton study identified a potential behavioural effect, not a health emergency. Most children will never consume enough to notice any difference.

Are E-numbers bad for you?

The Southampton Six are just six out of hundreds of E-numbers used in food. Many E-numbers are perfectly safe — some are even vitamins (vitamin C is E300, for example). The "E" simply means the additive has been assessed and approved for use in Europe.

For a balanced look at which E-numbers are genuinely worth paying attention to and which are harmless, see our article: Are E-numbers bad for you?

Frequently asked questions

What are the Southampton Six food colourings?

The Southampton Six are six artificial food colourings linked to increased hyperactivity in children by a 2007 University of Southampton study. They are: E102 (Tartrazine), E104 (Quinoline Yellow), E110 (Sunset Yellow FCF), E122 (Carmoisine/Azorubine), E124 (Ponceau 4R), and E129 (Allura Red AC). The study also included E211 (Sodium Benzoate), a preservative, in both test mixes.

Are the Southampton Six banned in the UK?

No, the Southampton Six are not banned in the UK or the EU. However, since 2010, any food or drink containing these colourings must carry a warning label stating: "may have an adverse effect on activity and attention in children." Most major UK manufacturers have voluntarily removed them from their products, but they can still be found in some cheaper sweets, imported foods, and certain medicines.

Do the Southampton Six cause ADHD?

The Southampton study did not find that these colourings cause ADHD. It found a statistically significant increase in hyperactive behaviour in children who consumed the test mixes compared to a placebo. ADHD is a complex neurodevelopmental condition with genetic and environmental factors. The study suggests these additives may affect behaviour in some children, not that they cause a clinical diagnosis.

How can I check if a product contains the Southampton Six?

Check the ingredients list on the packaging. Look for the E-numbers E102, E104, E110, E122, E124, or E129, or their common names: Tartrazine, Quinoline Yellow, Sunset Yellow, Carmoisine (Azorubine), Ponceau 4R, or Allura Red. Products containing these must also display the "may have an adverse effect on activity and attention in children" warning. You can also use a food scanner app to scan the barcode and get instant additive information.

Is sodium benzoate (E211) part of the Southampton Six?

Sodium benzoate (E211) was included in both test mixes in the Southampton study, but it is not formally counted among the "Southampton Six" colourings. It is a preservative rather than a colouring. Because it appeared in both mixes, researchers could not isolate its individual effect. E211 is still widely used in soft drinks, sauces, and processed foods in the UK.

Related articles

• Are E-Numbers Bad for You?
• What Are E-Numbers? A Complete UK Guide
• Food Additives and Children's Behaviour
• E-Numbers Database
• Food Additive Scanner UK

Last reviewed and updated: 7 February 2026