also: Food Green S · Acid Green 50 · Lissamine Green · Wool Green BS
A synthetic green dye made from coal tar, used to colour sweets, mint sauce, tinned peas and similar products.
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(As diluted):, Water, Lime Juice from Concentrate (5%), Sugar, Acid (Citric Acid), Flavourings, Preservative (Sodium Metabisulphite), Colours (Carotenes, Green S)
Not approved in the USA, Canada, Japan or Norway, partly because adequate long-term toxicity data are missing.
2
of the 43,325 UK supermarket foods we checked declare E142 in their ingredients
That is under 0.1%, counted by its code or its name.
Counted by NutraSafe from UK supermarket ingredient lists, September 2026. How we counted
Why it’s worth knowing. Not approved in the USA, Canada, Japan or Norway, partly because adequate long-term toxicity data are missing. At high consumption levels, children in EFSA's exposure modelling exceeded the acceptable daily intake. Human case reports include urticaria and asthma exacerbation in sensitive individuals.
Green S (also known as Acid Green 50, Food Green 4, CI 44090) is a water-soluble synthetic triarylmethane dye. It is produced from coal tar chemistry and exists as a dark blue-green powder or granule. The sodium salt form is used in food.
It absorbs red and yellow wavelengths of visible light, reflecting green, which gives foods a bright green colour. It is water-soluble but unstable in strongly acidic or alkaline solutions, which limits where it can be used.
Tinned mushy peas and garden peas, mint sauce, mint-flavoured confectionery, some desserts, gravy granules, ice creams, fish and crustacean pastes, and certain fruit spreads and jams. On a UK label it appears as 'colour (Green S)', 'colour (E142)', or 'E142'.
Green S belongs to the triarylmethane chemical class, which can break down into aromatic amine compounds. Some aromatic amines have mutagenic potential in laboratory tests. EFSA's 2010 re-evaluation noted the absence of adequate genotoxicity studies as a data gap, but pointed to negative findings from long-term carcinogenicity and reproductive toxicity animal studies as partial reassurance. European specifications for E142 therefore limit unsulfonated primary aromatic amine contaminants from the manufacturing process to no more than 0.01% (calculated as aniline).
The EFSA Panel identified a lack of adequate genotoxicity data for Green S as a matter of discussion, noting the gap is partially offset by negative carcinogenicity and reproductive toxicity results in animals.
Purity specifications for E142 cap unsulfonated primary aromatic amines at 0.01% (calculated as aniline) to minimise mutagenic contaminants from synthesis.
EFSA modelled dietary exposure at different tiers of detail. Using maximum permitted use levels (Tier 2), intake estimates for children at the 95th and 97.5th percentile exceeded the ADI of 5mg per kilogram body weight per day. When more realistic consumption assumptions were applied (Tier 3 refined estimates), children's intake fell within the ADI. Adults did not exceed the ADI at either tier. This finding means children who eat large amounts of the foods that contain Green S may consume more than the level regulators consider acceptable.
At Tier 2 (maximum use levels), children's estimated daily intake at the 95th/97.5th percentile exceeded the ADI of 5mg/kg bw/day. Tier 3 refined estimates did not exceed the ADI for children or adults.
Human case reports have documented allergic-type reactions in sensitive people, including urticaria (hives) and asthma exacerbation. These reports are part of the basis for the US, Canadian, and Japanese decisions not to approve the dye. The reactions are not thought to be common in the general population, but people who know they react to synthetic food dyes may wish to check labels for E142.
Human case reports associate Green S with urticaria and asthma exacerbation in sensitive individuals. The USA, Canada, and Japan cite inadequate chronic-toxicity data and hypersensitivity reports as reasons for not authorising the dye.
The WHO/FAO Joint Expert Committee on Food Additives (JECFA) allocated a temporary ADI of 25mg per kilogram body weight per day in 1970 but withdrew it in 1975 and has not allocated a numerical ADI since. The EU's Scientific Committee on Food set its own ADI of 5mg/kg bw/day in 1984, which EFSA confirmed at re-evaluation in 2010. The divergence between JECFA (no ADI) and the EU (5mg/kg) reflects the limited toxicological dataset rather than a finding of harm.
JECFA established a temporary ADI of 25mg/kg bw/day in 1970, then withdrew it in 1975. No numerical ADI for Green S has been allocated by JECFA since.
The EU Scientific Committee on Food set an ADI of 5mg/kg bw/day in 1984. EFSA's 2010 re-evaluation found no reason to revise this figure, based on available absorption, subchronic, reproductive, developmental, and long-term toxicity data.
Green S is sometimes incorrectly grouped with the six artificial colours studied in the McCann et al. 2007 Southampton study (E102, E104, E110, E122, E124, E129). E142 was not included in that study and does not carry the hyperactivity warning label that EU and UK law requires for those six specific dyes.
The McCann et al. 2007 Southampton study tested mixtures containing E102, E104, E110, E122, E124, and E129 plus sodium benzoate. E142 was not part of either mixture tested.
People who experience reactions to synthetic food dyes (including hives, skin rashes, or asthma triggered by colourings) should check labels for 'Green S', 'E142', or 'colour (E142)'. Parents limiting synthetic dye intake for children should note that at high consumption levels, children's intake may approach or exceed the regulatory ADI.
Green S sits in an unusual regulatory position: approved in the UK and EU but rejected by the USA, Canada, Japan, and Norway. The core issue is a thin toxicological dataset. EFSA confirmed the existing ADI in 2010 but acknowledged missing genotoxicity studies. The dye is not one of the Southampton Six hyperactivity colours, so the EU/UK warning label requirement for those dyes does not apply. Exposure modelling shows children eating large quantities of Green S-containing foods could exceed the ADI at maximum permitted levels, though more realistic consumption estimates keep them within it. A 2024 review in the journal Food Safety and Health found no recent clinical or in vitro studies specifically addressing its human toxicity, describing limited new research rather than new harms. The picture is one of regulatory caution about data gaps rather than demonstrated harm at typical eating levels.
No. E142 Green S is approved for use in the UK under assimilated EU Regulation 1333/2008. It can be used in a defined set of foods including tinned peas, mint sauce, confectionery, and fish paste, subject to maximum use levels.
Those countries have not authorised E142, citing inadequate long-term toxicity data and human case reports of hypersensitivity reactions including hives and asthma exacerbation. The dye has never received food approval from the US FDA. Norway also does not authorise it, though the specific regulatory history of Norway's non-approval has not been confirmed from primary official sources.
Tinned mushy peas and garden peas, mint sauce, mint-flavoured sweets and confectionery, some desserts and ice creams, gravy granules, and certain fish and crustacean pastes. It appears on labels as 'colour (Green S)', 'colour (E142)', or 'E142'.
Yes. Green S is a wholly synthetic dye derived from coal tar chemistry and contains no animal-derived ingredients. It is suitable for vegans and vegetarians.
Last reviewed: 20 June 2026
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