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    INTERNATIONAL PROGRAMME ON CHEMICAL SAFETY

    WORLD HEALTH ORGANIZATION



    SUMMARY OF TOXICOLOGICAL DATA OF CERTAIN FOOD ADDITIVES



    WHO FOOD ADDITIVES SERIES NO. 12






    The data contained in this document were examined by the
    Joint FAO/WHO Expert Committee on Food Additives*
    Geneva, 18-27 April 1977




    Food and Agriculture Organization of the United Nations
    World Health Organization



    * Twenty-first Report of the Joint FAO/WHO Expert Committee on Food
    Additives, Geneva, 1977, WHO Technical Report Series No. 617

    YELLOW 2G

    EVALUATION FOR ACCEPTABLE DAILY INTAKE

    BIOLOGICAL DATA

    BIOCHEMICAL ASPECTS

         Injection of 1 mg/kg bw i.v. into adult rats as an aqueous
    solution resulted in 96% excretion in the bile (Ryan and Wright,
    1961). It has been suggested that the biliary excretion rate is
    related to the relative protein-binding properties of the dye in liver
    and blood (Priestly and O'Reilly, 1966). It is possible that Yellow 2G
    is metabolized in a similar manner to tartrazine which has a structure
    related to Yellow 2G (Gaunt et al., 1971; Walker, 1970; Westöö, 1965).
    Incubation of Yellow 2G with a buffered bacterial suspension from rat
    intestine for four hours at 37° under oxygen-free nitrogen resulted in
    38% azo-reduction of the colour (Roxon et al., 1967).

    TOXICOLOGICAL STUDIES

    Acute toxicity

         No information available.

    Short-term studies

    Rat

         Yellow 2G was fed to four groups of 15 male and 15 female rats at
    dietary levels of 0, 100, 1000 or 10 000 ppm for 13 weeks. The
    colourant was decolourized in the caecum yielding a colourless product
    which turned red on exposure to the air. No adverse effects were seen
    in the rate of body weight gain, or in the results of haematological
    examinations, serum chemistry, renal cell excretion and concentration
    tests. No gross or micropathological effects were detected which could
    be attributed to the colourant. There were isolated changes of the
    weights of kidney, small intestine, adrenal glands and testes in rats
    receiving 1000 or 10 000 ppm Yellow 2G but these were not considered
    to be related to treatment. The caeca were enlarged in rats fed a diet
    containing 10 000 ppm (Gaunt et al., 1971).

    Pig

         Four groups of three pigs of each sex were given Yellow 2G in
    doses of 0 (control), 5, 50 or 500 mg/kg/day for 15 weeks. The faeces
    of the pigs at the two higher dose levels developed a reddish colour
    on exposure to the air, probably due to oxidation of a metabolite of

    the colouring. There was an initial diarrhoea lasting one or two days
    in half the pigs at the highest dose level. No adverse effects were
    seen in the rate of body weight gain, haematology, examination of
    urine, organ weights or histopathological examination (Gaunt et al.,
    1975).

    Long-term studies

    Mouse

         Groups of 48 male and 48 female mice (TF1 strain) were given
    diets containing 0 (control), 30, 300 or 1500 ppm Yellow 2G (purity
    min. 85%) for 80 weeks. Additional groups of 16 male mice were given
    diets containing 0 or 1500 ppm of the colour. There was a non-
    significant reduction in rate of body weight gain at the two higher
    dietary levels in males and isolated lower values for haemoglobin
    concentration and erythrocyte count at these same levels in both
    sexes. These findings together with increased values for relative
    brain, liver and small intestine weight in the females given 1500 ppm
    Yellow 2G were not considered to be related to treatment. There were
    deaths in all groups during the study but at no time were there
    significant differences between the groups. There were no effects
    attributable to treatment in the incidence of histological lesions.
    The most frequent kind of tumour in the mouse were lymphomas, but
    there was no significant statistical difference between the groups
    (Evans et al., 1975).

    Rat

         Groups of 48 male and 48 female rats (Wistar strain) were given
    diets containing 0 (control), 100, 1000 or 10 000 ppm of Yellow 2G
    (purity min. 85%) for 2 years. There were no treatment-related effects
    on mortality, food and water intake, serum analyses or haematology.
    There were slight decreases of weight gain in animals on the highest
    dietary level and a decreased renal concentrating ability at week 104
    in rats given 1000 or 10 000 ppm together with an increased kidney
    weight in males on the highest level. Glomerulonephrosis was seen in
    the majority of the animals, but there was essentially no difference
    between treated and control animals, except in the low dose F where
    there were significantly more "slight to moderate" (but less "severe")
    lesions than in the controls.

         The changes in kidney function and morphology are most likely an
    expression of spontaneous degeneration which is normal in old
    laboratory rats. The differences are most probably fortuitous and not
    due to treatment with Yellow 2G. Most of the histopathological lesions
    found were with similar frequencies in control and test animals. The
    other findings were not dose-related. Most of the tumours were found
    in controls alone or with similar frequencies in control and treated

    animals. The other tumours of different type were found scattered
    through all the groups but not dose-related. It was concluded that
    Yellow 2G did not exert a carcinogenic effect in this experiment
    (Hooson et al., 1975).

    REFERENCES

    Evans, J. G., Gaunt, I. F., Kiss, I. S. and Butterworth, K. R. (1975)
    Longterm toxicity of Yellow 2G in mice, BIBRA research report No.
    13/1975

    Gaunt, I. F. et al. (1971) Fd. Cosmet. Toxicol., 9, 343

    Gaunt, I. F. et al. (1975) Fd. Cosmet. Toxicol., 13, 1-5

    Hooson, J., Gaunt, I. F., Hardy, J., Gangolli, S. D. and Butterworth,
    K. R. (1975) Longterm toxicity study of Yellow 2G in the rat, BIBRA
    research report No. 18/1975

    Priestly, B. G, and O'Reilly, W. J. (1966) J. Pharm. Pharmacol.,
    18, 41

    Roxon, J. J., Ryan, A. J. and Wright, S. E. (1967) Fd. Cosmet.
    Toxicol., 5, 367

    Ryan, A. J. and Wright, S. E. (1961) J. Pharm. Pharmacol., 13, 492

    Westöö, G. (1965) Acta. Chem. Scand., 19, 1309

    Walker, R. (1970) Fd. Cosmet. Toxicol., 8, 659


    See Also:
       Toxicological Abbreviations
       Yellow 2G (WHO Food Additives Series 6)
       YELLOW 2G (JECFA Evaluation)