E129

Allura Red AC (Red 40)

Last reviewed: 11 May 2026

Synthetic red azo dye — Southampton Six, FSA warning required

What is E129?

E129 is Allura Red AC, a synthetic bright-red azo dye derived from petroleum. In UK products it's the workhorse red — alongside E122 Carmoisine, the most heavily used red in soft drinks and sweets that carry the Southampton warning. Introduced in the 1970s as a replacement for E123 Amaranth.

Also known as: Red 40 (US name), FD&C Red No. 40, Allura Red, C.I. Food Red 17.

It's used because it's stable through heat and light, holds its tone in acidic drinks, and is cheaper than natural red alternatives like beetroot.

Where you'll see E129 on a UK label

Sweets and confectionery

• Red gummy bears and jelly sweets
• Red liquorice and chewy strips
• Lollipops, fruit chews and hard-boiled sweets

Drinks

• Red soft drinks — strawberry, cherry, raspberry, fruit-punch flavours
• Energy drinks
• Flavoured squash and cordials

Other foods

• Ice lollies and some ice creams
• Cake decorations and icing
• Instant dessert mixes (jelly, Angel Delight, Instant Whip)
• Some sauces and condiments
• Coloured-piece breakfast cereals

Non-food uses

• Children's liquid medicines
• Cosmetics

The Southampton Study and the UK warning rule

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

Since 2010, UK and EU food law has required this warning 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.

Cross-reactivity with aspirin and NSAIDs

E129 is an azo dye structurally related to salicylates. The published clinical literature describes cross-reactivity in people sensitive to aspirin (acetylsalicylic acid) and other NSAIDs. Reported reactions include:

• Hives (urticaria) and skin rashes
• Itching, facial swelling (rare)
• Bronchoconstriction in people with aspirin-induced asthma
• Cross-reactivity with other azo dyes — people who react to E102, E110, E122 or E124 often react to E129

Azo-dye breakdown and animal-study signals

Azo dyes like E129 are reduced by gut bacteria to aromatic amines. The long-term toxicological significance of these breakdown products under chronic dietary exposure remains under investigation. Older rodent studies (1970s onwards) reported tumour signals at very high doses; the EFSA position is that the established ADI does not present a meaningful cancer risk at normal consumption, while keeping the dye under continued review. The US Center for Science in the Public Interest (CSPI) has campaigned for stricter regulation of Red 40 on behavioural-effect grounds.

Regulatory status

UK / EU: approved with an ADI of 7mg/kg body weight per day. The Southampton warning is mandatory on any product containing E129.

US: FDA approved as Red 40. No warning label required, but the dye must be named on the ingredient list. It's the most heavily used red dye in the US food supply.

Norway and Iceland: historically restricted.

Who has the strongest reason to avoid E129

• 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 reactive to other azo dyes (E102, E110, E122, E124)
• People with chronic urticaria — case reports of worsened hives

Red alternatives on UK labels

Manufacturers replacing E129 typically reach for plant- or insect-derived colours:

• Beetroot extract (E162) — purple-red
• Anthocyanins (E163) — from berries, red cabbage
• Carmine / cochineal (E120) — insect-derived, not vegan
• Paprika extract (E160c) — orange-red
• Lycopene (E160d) — from tomatoes

None carry the Southampton warning.

Reading a UK label

Look for "E129", "Allura Red AC", "Allura Red", or "colour: E129" in the ingredient list, and look for the FSA warning sentence under the ingredients. The warning is small print, but is mandatory. US imports may list "Red 40" or "FD&C Red No. 40" — same molecule, no warning required there.

Last updated: 11 May 2026