Tartrazine

What is E102?

E102 is Tartrazine, a synthetic lemon-yellow azo dye. It was first synthesised in 1884 from coal-tar chemistry and is now produced from petroleum. It's one of the most heavily studied of the Southampton dyes.

Also known as: Yellow 5 (US name), FD&C Yellow No. 5, C.I. Food Yellow 4, CI 19140, E102.

It's used because it's cheap, heat- and light-stable, and produces a strong yellow tone in products with no natural yellow ingredient.

Where you'll see E102 on a UK label

Drinks

• Lemon squash and lemonade
• Some energy and sports drinks
• Flavoured cordials

Sweets and desserts

• Jelly sweets, lollipops, hard-boiled sweets
• Yellow or green coloured icing
• Custard powder and instant dessert mixes

Savoury and packaged foods

• Mushy peas and tinned processed peas
• Cheese-flavoured crisps and corn snacks
• Packet soups, instant noodles, curry sauces
• Pickles and some salad dressings

Non-food uses

• Liquid medicines and vitamin supplements (often children's formulations)
• Cosmetics

The Southampton Study and the UK warning rule

The 2007 Southampton Study (published in The Lancet) tested E102 alongside five other dyes — E104, E110, E122, E124, E129 — and the preservative E211 (sodium benzoate), in children aged 3 and 8–9. The study reported increased hyperactivity and reduced attention scores, with effects observed across the general child population, not only children with ADHD diagnoses.

Since 2010, UK and EU food law has required a warning label on any product containing one of these six dyes:

"May have an adverse effect on activity and attention in children."

The dyes are commonly referred to as the Southampton Six. E102 was the most-cited dye in the study.

Cross-reactivity with aspirin and NSAIDs

E102 is structurally similar to salicylates. The published clinical literature describes cross-reactivity in people sensitive to aspirin (acetylsalicylic acid) and other NSAIDs (ibuprofen, naproxen). Reported reactions include:

• Hives (urticaria), rashes and itching
• Rhinitis — runny nose, sneezing
• Bronchoconstriction, particularly in people with aspirin-induced asthma
• Migraine in some individuals

Allergy and asthma specialists routinely advise sensitive patients to avoid the dye. True E102 IgE allergy is rare (under 0.1% of the population); aspirin-pattern cross-reactivity is the more common mechanism.

Azo-dye breakdown in the gut

Azo dyes like E102 are reduced by gut bacteria to aromatic amines. The long-term toxicological significance of these breakdown products under chronic dietary exposure remains under investigation; the published literature is mixed and regulators have not closed the question.

Regulatory status

UK / EU: approved with an ADI of 7.5mg/kg body weight per day. The Southampton warning is mandatory on any product containing E102.

US: FDA approved as Yellow 5. No warning label required, but the dye must be named on the ingredient list.

Norway: banned until 2001; now permitted with restrictions.

Who has the strongest reason to avoid E102

• People with aspirin or NSAID intolerance — meaningful cross-reactivity rate
• People with asthma, especially aspirin-triggered asthma
• Children with diagnosed ADHD — Southampton-study evidence
• Anyone with chronic urticaria — case reports of worsened hives
• People with additive-triggered migraine

For the general child population the regulator's response was the warning label rather than a ban — parents who want to act on the Southampton findings can use the FSA warning as a shopping signal.

Yellow alternatives on UK labels

Manufacturers replacing E102 typically reach for plant-derived colours:

• Curcumin (E100) — natural yellow from turmeric
• Riboflavin (E101) — vitamin B2
• Beta-carotene (E160a) — from carrots and other plants
• Annatto (E160b) — yellow-orange from achiote seeds

None carry the Southampton warning.

Reading a UK label

Look for "E102", "Tartrazine", or "colour: E102" in the ingredient list, and look for the FSA warning sentence under the ingredients. The warning is small print, but is mandatory.