Ponceau 6R
A red synthetic azo dye removed from all UK and EU permitted food colour lists in 1994 after regulators could not establish a safe daily intake.
Ponceau 6R is no longer permitted in food sold in the UK or EU. If you have asthma or react to aspirin, azo dyes as a class can trigger breathing difficulties and hives in a subset of sensitive people.
What is it?
Ponceau 6R (also called Crystal Scarlet and Acid Red 44) is a synthetic monoazo dye that produces an intense red colour. It is water-soluble and exists as a disodium salt. It was formerly used as a food colour and retains a laboratory use as a fibrin stain in histological trichrome procedures (the MSB technique).
What does it do?
As a food colour it absorbs light at around 510-513 nm, giving food a red to crimson appearance. It works purely cosmetically, adding or restoring red colour in processed products. In the laboratory it binds selectively to fibrin protein, making it useful for staining tissue sections.
Where you will see it
Ponceau 6R is not permitted in UK or EU food, so it should not appear on any ingredient list in products sold here. Historically, before its removal in 1994, it was used in confectionery, sodas, jams, fruit preserves, canned fish and seafood products, and bakery goods. Any food product carrying this colour and sold in the UK or EU would be non-compliant. On a label it would appear as 'Ponceau 6R' or 'E126'.
What the science says
JECFA could not set a safe daily intake
The Joint FAO/WHO Expert Committee on Food Additives (JECFA) evaluated Ponceau 6R multiple times between 1959 and 1977 and concluded it was not possible to establish an acceptable daily intake on the data available. The long-term animal studies that were conducted were described by JECFA as inadequate: they focused narrowly on carcinogenicity, used small numbers of animals, and lacked data on metabolism, reproduction, and embryotoxicity. JECFA withdrew its specifications for this additive in 1984.
JECFA evaluated Ponceau 6R in 1974 and recorded 'No ADI allocated - not possible on the data provided', citing absent metabolic data, inadequate animal numbers, and missing reproduction studies.
At its 1977 meeting JECFA deferred a decision on Ponceau 6R again, and the specifications were formally withdrawn in 1984, indicating the additive was removed from consideration for food use.
Removed from EU and UK permitted colours lists in 1994
When the European Community replaced its original 1962 colours directive with Directive 94/36/EC on colours for use in foodstuffs, Ponceau 6R was one of seven artificial colours deleted from the positive list. The deletion was based on the Scientific Committee on Food's ongoing review of toxicological data. The UK's Colours in Food Regulations 1995, which implemented the directive domestically, did not include E126. Current UK law (assimilated EU Regulation 1333/2008) does not list E126 as a permitted food colour.
Ponceau 6R was among seven artificial colours (alongside Chrysoine S, Fast Yellow AB, Orange GGN, Scarlet GN, Anthroquinone Blue and Black 7984) deleted from the EU positive list when Directive 94/36/EC replaced the 1962 colour directive, based on the Scientific Committee on Food's toxicological evaluation.
E126 does not appear in the UK FSA's current approved additives and E numbers list, nor in the schedule of permitted colours in the UK's assimilated food additives legislation.
Azo dye class: aspirin sensitivity and potential reactions
Ponceau 6R belongs to the azo dye class. Azo dyes are metabolised in the gut to aromatic amine breakdown products. In people who are sensitive to aspirin or non-steroidal anti-inflammatory drugs, azo dyes as a class have been reported to trigger asthma, urticaria and other reactions, though controlled challenge studies suggest confirmed reactions are far less common than patients report. The JECFA monograph specifically noted that sensitivity reactions had been reported in people allergic to benzoates and aspirin.
The JECFA monograph on Ponceau 6R recorded that sensitivity reactions in people allergic to benzoates and aspirin had been reported (citing Michaelson and Juhlin, 1973).
A controlled oral challenge study found that confirmed hypersensitivity to azo dyes in urticaria patients is much less common than patient self-report suggests, with only around 5% of challenged patients showing a positive reaction.
Azo dyes as a class are metabolised by intestinal microflora to aromatic amines, which are further activated by liver enzymes and have potential genotoxic properties in laboratory models.
Animal study findings were limited and carcinogenicity-focused
The long-term animal studies conducted on Ponceau 6R were designed only to detect carcinogenicity and used small animal numbers. One rat developed a tumour of possible pancreatic origin in a dietary study, but JECFA judged the evidence insufficient to draw conclusions. The studies were not structured to detect organ toxicity broadly. Claims that animal studies showed serious disorders of the liver, kidneys, ureters and bladder circulate in some secondary sources but are not supported by the primary JECFA monograph text, which reports no such findings and explicitly describes the studies as inadequate.
JECFA's 1974 monograph noted that long-term studies with Ponceau 6R 'aimed solely at discovering potential carcinogenicity and therefore did not include the detailed observations usually made in these tests,' and that the small animal numbers made them inadequate for assessing long-term toxicity.
Where it stands with the regulators
Who should be careful
Everyone in the UK and EU: this colour is not permitted in food sold here. People with asthma or a known sensitivity to aspirin should be aware that azo dyes as a class have been associated with breathing difficulties and skin reactions in some individuals, and should check ingredient lists on imported food products for 'Ponceau 6R' or 'E126'.
The honest read
The key facts here are unusually clear. Ponceau 6R is banned from food in the UK and EU, not because of a single dramatic toxicological finding but because regulators could never accumulate enough reliable data to say how much of it was tolerable. JECFA tried three times over nearly two decades and gave up. The EU then removed it from the permitted list entirely in 1994. The animal studies that do exist were narrow in scope and used too few animals to be informative. Secondary sources sometimes repeat claims about severe kidney, liver and bladder damage from animal studies; the actual JECFA monograph does not support those claims and explicitly calls the studies inadequate. The legitimate concern is the regulatory one: this dye never cleared the bar required for food use and has been absent from UK food law for over 30 years.
Related additives
Common questions
Is E126 banned in the UK?
Yes. Ponceau 6R was removed from the EU's permitted food colour list under Directive 94/36/EC in 1994, based on the EU's Scientific Committee on Food concluding that available toxicological data was insufficient to establish a safe intake. The UK's Colours in Food Regulations 1995 did not include it, and current UK assimilated food additives law (retained EU Regulation 1333/2008) likewise does not list it. It has not been a permitted food colour in the UK for over 30 years.
Why was Ponceau 6R removed from the permitted list?
The Joint FAO/WHO Expert Committee on Food Additives (JECFA) evaluated Ponceau 6R multiple times between 1959 and 1977 and was unable to establish an acceptable daily intake. The long-term animal studies available were judged inadequate: they were designed only to look for cancer, used small numbers of animals, and provided no metabolic data or reproduction studies. JECFA withdrew its specifications in 1984. When the EU updated its colours directive in 1994, the Scientific Committee on Food's toxicological review led to Ponceau 6R being deleted from the positive list alongside six other artificial colours.
What foods contain E126?
No food legally sold in the UK or EU should contain E126. Before its removal in 1994, it was used in confectionery, fizzy drinks, jams, fruit preserves, canned fish, seafood products and bakery goods. If you see E126 or 'Ponceau 6R' on a label in the UK it would indicate a non-compliant product, potentially an import from outside the EU.
Is E126 vegan?
Yes, Ponceau 6R is a fully synthetic azo dye and contains no animal-derived ingredients. The question is moot for UK and EU shoppers, however, as it is not permitted in food sold here.
Sources
- JECFA Evaluations - Ponceau 6R (evaluation history 1959-1977, specifications withdrawn 1984)
- JECFA Monograph 380: Ponceau 6R (WHO Food Additives Series 6, 1974)
- UK Food Standards Agency: Approved Additives and E Numbers
- UK Colours in Food Regulations 1995 (SI 1995/3124)
- EU Directive 94/36/EC on colours for use in foodstuffs
- NATCOL: Food Colours Legislation - full article (documents deletion of seven colours in 1994 directive)
- Mlynek et al., Hypersensitivity of azo dyes in urticaria patients based on single-blind placebo-controlled oral challenge, PMC9704453
- Mutagenicity of azo dyes: structure-activity relationships, Food and Chemical Toxicology
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