Sunset yellow FCF was last evaluated by the Joint FAO/WHO Expert
    Committee on Food Additives in 1964 (see Annex I, ref. 8).

         Since the previous evaluation, additional data have become



         When rabbits were fed 0.5 g/kg bw of the colour, the following
    metabolites could be identified in 48 hours urine: sunset yellow (2%),
    sulfanilic acid (54%), p-acetamido benzene-sulfonic acid (23%),
    1-amino-2-naphthol-6-sulfonic acid (55% in 24 hours) (Daniel, 1962).

         Rats were given a single oral dose of 100 mg of the colour per
    animal. Only 0.8% of the dose administered was found in the faeces.
    After a single oral dose of 50 mg only 3.6% was absorbed from
    the gastrointestinal tract. The metabolites in the urine were
    predominantly products resulting from the reductive fission of the
    azolinkage. The liver enzyme that reduces azolinkages plays little
    part in metabolism. Reduction of the colour by the intestinal
    bacteria is therefore the most probable way to aromatic amines and
    aminosulfonic acids; these are then partly absorbed by the intestinal
    tract (Radomski & Mellinger, 1962).

         Rats were injected the colour intravenously. The bile was
    collected for 6 hours and analysed. The average recovery of the colour
    was 22% (20-30%) of the administered quantity (Ryan & Wright, 1961).

         Fourteen rats were dosed with sunset yellow within the range of
    2-25 mg and within 72 hours excreted 0.3 and 1.5% of the administered
    dye in urine and bile respectively and 37% of the sulfanilic acid
    equivalents in the urine.

         In 5 animals dosed with 14C-sunset yellow (2.7 mg, 4.62 µCi)
    after 96 hours urinary excretion of radioactivity was 8.5 ± 3.4% of
    the dose. The 24 hours urine collection from the sunset yellow rats
    contained 40% of the molar equivalents of sulfanilic acid. Intact dye
    in the 24 hours urine represented 1-2% of the dose. Peak faecal
    excretion occurred during the first 24 hours. The recovery of
    radioactivity was 94.5 ± 5.7%. Total recovery of radioactivity was
    103 ± 3.3% (Honohan et al., 1977).


    Special studies on cell cultures

         Sunset yellow FCF did not induce cell transformation using the
    F 1706 Fisher rat embryo fibroblasts even after 10 subcultures, i.e.
    no typical morphological alterations were noted and the cells were not
    significantly tumorigenic (Price et al., 1978).

    Special studies on multigeneration reproduction

         Doses of sunset yellow FCF were administered in the diet, and
    were based on multiples (1x, 10x, 30x, and 100x) of the ADI or of the
    projected safe dose determined from data of previous long-term
    feeding studies in rats and dogs. However, no doses in excess of
    1000 mg/kg/day were used. The human usage level of the colour was also
    a factor in determining the levels used in the diet. Data through the
    F2b litter gave no indication of adverse effects on reproductive
    performance (Pierce et al. 1973 - available in summary only).

    Special studies on mutagenicity

         The colour was tested for mutagenic activity in a concentration
    of 0.5 g/100 ml in cultures of Escherichia coli. No mutagenic effect
    was found (Luck & Rickerl, 1960).

         Sunset yellow FCF was not mutagenic in Salmonella typhimurium
    strains TA 1538, TA 98 or TA 100, with or without metabolic
    activitation. Various sulfonated naphthylamines were also without
    mutagenic activity (e.g. 1-amino-2-naphthol-4-sulfonic acid) (Garner &
    Nutman, 1977).

         Sunset yellow did not produce reverse mutations in 4 strains
    (TA 1535, TA 1538, TA 98, TA 100) of Salmonella typhimurium when
    tested in presence and absence of liver microsomal (S9) fractions
    obtained from rats pretreated with phenobarbitone (Viola & Nosotti,

         Sunset yellow FCF did not cause any increase in mitotic gene
    conversion in diploid yeast B2 34 (S. cerevisiae) (Sankaranarayanan
    & Murthy, 1979).

         Sunset yellow was studied for its ability to cause DNA-damage in
    an E. coli rec assay. Reverse mutations were studied in E. coli WP
    2 uvrA and S. typhimurium TA 1538 in fluctuation assays. Both types
    of assays were conducted with and without metabolic activation. Sunset
    yellow FCF did not demonstrate genotoxicity (Haveland-Smith & Combes,

    Special studies on teratogenicity

         Sunset yellow FCF was administered to rats by gavage at dose
    levels of 100, 300 and 1000 mg/kg/day on days 6 through 15 of
    gestation. The mean weight of offspring of the dams which received 300
    and 1000 mg/kg/day were decreased, but the effect was of doubtful
    significance. No effect was observed on any other maternal (body
    weight, corpora lutea, empty implantation sites, early resorptions,
    late resorptions, and live or dead term foetuses) or foetal (sex,
    external, internal and skeletal abnormalities) parameters evaluated.
    No terata were observed in the offspring of these dams (International
    Research and Development Corporation, 1972a).

         Sunset yellow FCF was administered to rabbits by gavage at
    dosage levels of 100, 300 and 1000 mg/kg/day on days 6 through 18 of
    gestation. No effect was observed on any maternal (body weight,
    corpora lutea, early and late resorptions, and live or dead term
    foetuses) or foetal (mean body weight, sex, external and skeletal
    abnormalities) parameters evaluated. An incomplete twin which was not
    considered compound related occurred at the 1000 mg/kg/day level
    (International Research and Development Corporation, 1972b).

    Acute toxicity

    Animal      Route      (mg/kg bw)            Reference

    Mouse       Oral          >6 000         Gaunt et al., 1967

                i.p.           5 000         Gaunt et al., 1967

    Rat         Oral          >2 000         Lu & Lavallée, 1967

                Oral         >10 000         Gaunt et al., 1967

                i.p.           3 800         Gaunt et al., 1967

    Short-term studies


         Groups of 10 immature female rats were given the colour
    subcutaneously twice daily for 3 days. The rats were killed on the
    fourth day. The colour was administered in aqueous solution at a level
    of 250 mg/kg bw each injection. No oestrogenic activity (uterine
    weight) was detected (Graham & Allmark, 1969).

         Twenty rats were given subcutaneously 1 ml of a 1% solution of
    the colour twice a week for 7 months. Totally 55 injections were
    given. Only 1 intraperitoneal tumour was found (the observation period
    was not mentioned) (Deut. Forsch., 1957).

         The colour was given to a group of 16 rats as a 2% solution in
    the drinking-water for 10 months. The diet of these rats was
    suboptimal in vitamin B2. In comparison with a group without the
    colour, it was noticed that the colour accelerated the growth of the
    young rats and improved the survival rate of these animals. No
    histopathological changes in the liver were observed (Manchon & Lowy,

         Feeding of sunset yellow FCF to groups of 15 male and 15 female
    rats at dietary levels of 0 (control), 0.5, 1.0, 2.0 or 3.0% for 90
    days evoked no adverse effect on growth or food consumption but there
    was slight diarrhoea throughout the study at 3% and during the first
    few weeks at 2%. There was no departure from normality in the
    haematological investigations or in the terminal liver and kidney
    function tests. At autopsy, the caecum was enlarged at the 2 and 3%
    levels and the testes at the 3% level. There were no histological
    changes attributable to sunset yellow FCF (Gaunt et al., 1967).


         In experiments with guinea-pigs it was found that this colour had
    no sensitization activity (Bär & Griepentrog, 1960).

    Miniature pig

         Sunset yellow FCF was fed to groups of 3 male and 3 female pigs
    at levels of 0 (control), 250, 500 and 1000 mg/kg/day for 98 days. No
    differences were detected between test and control animals in weight
    gain, haematological indices, composition of urine, organ weights or
    serum levels of transaminases and urea. No abnormalities were seen at
    autopsy or on microscopical examination of the tissues (Gaunt, 1969).

    Long-term studies


         A group of 30 mice were given 0.05% of the colour in their
    drinking-water for 52 weeks. The animals were kept for their lifespan.
    The weekly ingestion of the colour was about 17 mg and totally 884
    mg/mouse. Nine lymphomas and one benign intestinal tumour were found
    in 7 survivors. In the controls, 5 lymphomas and one intestinal tumour
    were found in 13 survivors. There were 60 mice in the control groups
    at the beginning of the experiment (Bonser et al., 1956).

         Two-year feeding studies were conducted with this colour using 2
    strains of mice; C57 black and C3H at levels of 1 and 2%. One
    hundred animals of each strain were fed the colour at both dosage
    levels and 200 animals of each strain were fed a control diet. There
    was no effect on tumour formation (FDA, 1964).

         Groups of 30 male and 30 female mice were given diets containing
    0.2, 0.4, 0.8 or 1.6% sunset yellow FCF for 80 weeks. A group of 60
    male and 60 female mice served as controls. The feeding of sunset
    yellow FCF did not adversely affect the death rate within the groups,
    the rate of body weight gain, the organ weights or the haematological
    findings. The incidence and severity of the histopathological findings
    were similar in treated and control mice and there was no evidence of
    an increased incidence of tumours in the mice given sunset yellow FCF
    (Gaunt, 1974).


         In 11 Graffi or Lakeview (LVG) suckling hamsters, sunset yellow
    FCF (1.0 mg) injected either subcutaneously or intraperitoneally did
    not increase mortality and no tumours were detected over a 330-day
    period (Price et al., 1978).


         Five male and 5 female rats were given the colour at a level of
    4% in the diet for periods up to 18 months. There was some staining of
    the glandular stomach and small intestine and in some animals granular
    deposits were observed in these organs. No tumours were observed
    (Willheim & Ivy, 1953).

         Four groups of 15 male and 15 female rats were given diets with
    0, 0.03, 0.3 and 1.5% of the colour for 64 weeks. The mortality of the
    rats was as in the control group. No influence on food intake, growth,
    organ weights, histopathology and blood picture was found. No
    significant difference in tumour incidence was found (Mannell, 1958).

         Groups of 24 litter-mated Osborne-Mendel rats, evenly divided by
    sex, were fed the colour at 0, 0.5, 1.0, 2.0 and 5.0%. There was a
    statistically insignificant increase in the number of mammary tumours.
    The number of tumours that were found in the different groups were
    respectively 2, 1, 6, 3 and 6.

         Additional feeding studies were conducted with Osborne-Mendel and
    Sprague-Dawley rats; 100 animals of each strain were fed at 1.0 and
    2.0%, and 200 of each strain were placed on the control level. Gross
    and microscopic pathology showed no effect on tumour formation (FDA,

         Four groups of 20 rats, both sexes, were used. Dietary levels of
    2.0, 1.0, 0.5, and 0.0% were fed. At the 79th and 102nd weeks, the

    survivors were sacrificed and autopsied. Slight but non-significant
    growth retardation occurred in female rats. Food consumption and
    survival were not affected. Histopathologically, in the liver there
    were only the usual changes found in older animals. No neoplastic
    change was seen in the rats and no carcinogenicity was detected
    (Kanisawa, 1967).


         Feeding studies with dogs were conducted; 4 beagles were fed the
    colour at each level of 1.0 and 5.0%. Two of the 4 animals at 5% and 1
    animal at 1.0% lost weight progressively and had to be sacrificed
    after 2-3 months. In general, 5.0% in the diet of dogs was moderately,
    and 1.0% was slightly, toxic. Weight loss and diarrhoea were the chief
    clinical effects. Gross and microscopic pathological changes were
    present but were not characteristic.

         Five female beagle dogs were fed the colour at 2.0% in the diet
    for 7 years. No histopathology was reported (FDA, 1964).


         A skin test with the colour showed in patients sensitive to
    p-phenyl-enediamine eczematous hypersensitivity produced by cross-
    sensitization. This reaction is explained by the ease of its
    transformation into compounds of quinone structure and upon the
    ability of the quinone compound to couple with certain body
    constituents (Baer et al., 1948).


         Several long-term studies have been carried out in rats. Long-
    term studies have also been carried out in mice, hamsters, and dogs.
    The biochemical studies indicate that in the rat this colour is
    reduced at the azo linkage by bacteria present in the intestine and
    that some of the breakdown products are absorbed and excreted in the
    urine. The Committee reconsidered earlier studies on this compound
    together with newer studies and decided to allocate a revised ADI.


    Levels causing no toxicological effect

    Rat: 1% in the diet, equivalent to 500 mg/kg bw.

    Dog: 2% in the diet, equivalent to 500 mg/kg bw.

    Estimate of acceptable daily intake for man

    0-2.5 mg/kg bw.


    Baer, R. L., Leider, M. & Mayer, R. L. (1948) Possible eczematous
         cross-hypersensitivity between p-phenylenediamine and azodyes
         certified for use in foods, drugs and cosmetics, Proc. Soc.
         exp. Biol. (N.Y.), 67, 489-494

    Bär, F. & Griepentrog, F. (1960) Die Allergenwirkung von Fremden
         Stoffen in den Lebensmitteln, Med. u. Ernahr., 1, 99-104

    Bonser, G. M., Clayson, D. B. & Jull, J. W. (1956) The induction
         of tumours of the subcutaneous tissues, liver and intestine in
         the mouse by certain dyestuffs and their intermediates, Brit.
         J. Cancer, 10, 653

    Daniel, J. W. (1962) The excretion and metabolism of edible colours,
         Toxicol. appl. Pharmacol., 4, 572-594

    Deutsche Forschungsgemeinschaft, Bad Godesberg, Federal Republic of
         Germany, Farbstoff Kommission (1957) Mitteilung 6

    EEC (1982) Report of the Scientific Committee for Food on the
         sensitivity of individuals to food components and food additives.
         In: Commission of the European Communities, Food Science and
         Technology, EUR 7823

    FDA (1964) Summary of toxicity data on colours: FD and C Yellow No. 6.
         Unpublished report from the U.S. Food and Drug Administration

    Garner, R. C. & Nutman, C. A. (1977) Testing of some azodyes and their
         reproduction products for mutagenicity using S. typhimurium
         TA 1538, Mutation Res., 44, 9-19

    Gaunt, I. F. et al. (1967) Acute (rat and mouse) toxicity studies on
         sunset yellow FCF, Fd Cosmet. Toxicol., 5, 747-754

    Gaunt, I. F. et al. (1969) Short-term toxicity study on sunset yellow
         FCF in the miniature pig, Fd Cosmet. Toxicol., 7, 9-16

    Gaunt, I. F. et al. (1974) Long-term toxicity of sunset yellow FCF
         in mice, Fd Cosmet. Toxicol., 12, 1-10

    Graham, R. C. & Allmark, M. G. (1959) Screening of some food colours
         for estrogenic activity, Toxicol. appl. Pharmacol., 1,

    Haveland-Smith, R. B. & Combes, R. D. (1980) Screening of food dyes
         for genotoxic activity, Fd Cosmet. Toxicol., 18, 215-221

    Honohan, T. et al. (1977) Intestinal absorption of polymeric
         derivatives of the food dyes sunset yellow and tartrazine in
         rats, Xenobiotica, 7, 765-774

    International Research and Development Corporation (1972a) FD & C
         yellow No. 6. Teratology study in rats. Unpublished report
         submitted to the Inter-Industry Colour Committee, No. 306-004

    International Research and Development Corporation (1972b) FD & C
         yellow No. 6. Teratology study in rabbits. Unpublished report
         submitted to the Inter-Industry Colour Committee, No. 306-003

    Kanisawa, H. et al., Chiba-Daigakn Fuhai Kenkynsho Kokokn (1967) 20,
         101-110. Chronic oral toxicity of sunset yellow FCF, Chem.
         Abstr. (1969) 70, 27250

    Lu, F. C. & Lavallée, A. (1964) The acute toxicity of some synthetic
         colours used in drugs and foods, Cand. pharm. J., 97, 30

    Luck, H. & Rickerl, E. (1960) Food additives and mutative effect.
         VI - Report, Z. Lebensmitt.-Untersuch., 112, 157

    Manchon, P. H. & Lowy, R. (1964) Effet pseudovitaminique du jaune
         soleil sur la croissance du rat, Fd Cosmet. Toxicol., 2,

    Mannell, W. A., Grice, H. C., Lu, F. C. & Allmark, M. G. (1958)
         Chronic toxicity studies on food colours. Part IV - Observations
         on the toxicity of tartrazine, amaranth and sunset yellow in
         rats. J. Pharm. Pharmacol., 10, 625

    Pierce, E. C. et al. (1974) Multigeneration reproduction studies with
         certified colours in rats. Inter-Industry Colour Committee Task
         Force, Cosmetic Toiletry and Fragrance Association, Inc.,
         Washington, D.C. Abst. XIII Ann. Meeting of Toxicol. appl.
         Pharmacol., 29, 121

    Price, P. J. et al. (1978) In vitro and in vivo indications of the
         carcinogenicity and toxicity of food dyes, Int. J. Cancer,
         21, 361

    Radomski, J. K. & Mellinger, T. J. (1962) The absorption rate and
         excretion in rats of the water-soluble azodyes FD & C Red No. 2,
         FD & C Red No. 4, FD & C Yellow No. 6, J. Pharmacol., 136,

    Ryan, A. J. & Wright, S. E. (1961) The excretion of some azodyes in
         rat bile, J. Pharm. Pharmacol., 13, 492

    Sankaranarayanan, N. & Murthy, M. S. S. (1979) Testing of some
         permitted food colours for the induction of gene conversion in
         diploid yeast, Mutation Res., 67, 309-314

    United States Food and Drug Administration, Unpublished report
         submitted to WHO, April 1964

    Viola, M. & Nosotti, A. (1978) Application of the Ames test on some
         dyes, Boll. Chim. Farm., 117, 402

    Willheim, R. & Ivy, A. C. (1953) A preliminary study concerning the
         possibility of dietary carcinogenesis, Gastroenterology, 23,

    See Also:
       Toxicological Abbreviations
       SUNSET YELLOW FCF (JECFA Evaluation)
       Sunset Yellow FCF (IARC Summary & Evaluation, Volume 8, 1975)