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    RED 2G

    Explanation

         This food colourant was evaluated by JECFA in 1977, and a
    temporary ADI for man of 0-0.006 mg/kg bw was established (WHO, 1978).
    Further work required included a multigeneration study, and studies on
    bone marrow to elucidate the toxic effects on erythropoiesis. In 1979
    none of these studies had been completed and JECFA extended the
    previously established temporary ADI (WHO, 1980).

         Since the previous evaluations, additional data have become
    available and are included in this monograph.

    BIOLOGICAL DATA

    BIOCHEMICAL ASPECTS

         Rats were injected intravenously with Red 2G. Bile was collected
    for six hours and analysed. The recovery of the colour was on average
    64% of the administered quantity (Priestly & O'Reilly, 1966). Biliary
    excretion of i.v. administered Red 2G was also reported by Ryan &
    Wright (1961).

         In another experiment 250 mg/kg bw of Red 2G was administered by
    gastric intubation to five male and five female rats. On average the
    males excreted 61.8% of the dose in the urine and the females 71.5%,
    42.2% of the dose was excreted in the urine as p-aminophenol in 48
    hours, 9.2% as aniline in 24 hours and 3% as unreduced dye in 24
    hours. The corresponding faecal excretion was 6.3, 1.0 and 0.1%. For
    females urinary excretion amounted to 56.4% as p-aminophenol in 48
    hours, 2% as aniline in 24 hours and 2.6% as unreduced dye in 24
    hours. The corresponding faecal excretion was 8.6, 0.3 and 1.6%
    (Walker, 1971).

         The contents of a rat caecum were incubated at 37C with a
    solution of Red 2G in isotonic saline. At one-hour intervals a sample
    of the incubate was filtered and Red 2G was estimated in the filtrate
    by measuring the optical density. Two metabolites of Red 2G were
    detected in the incubation mixture after separation by thin layer
    chromatography on silica plates. One was 2-amino-8-acetamido-1-
    naphtho-3,6-disulfonic acid, the other, aniline, was detected using
    two different solvent systems. When Red 2G was incubated at 37C with
    liver homogenate the same two metabolites were detected (Jenkins et
    al., 1966).

         When a mixture of Red 2G and caecal contents were incubated
    at 37C darkening at the surface was observed. This was attributed
    to oxidation of a metabolite of Red 2G, presumed to be a sulfur-

    containing compound. Two groups of 12 rats were fed purified diet and
    a purified diet containing 0.51% Red 2G respectively. Faeces were
    collected and it was calculated that 48.2% of the sulfur derived from
    Red 2G was excreted in the faeces (Unilever, 1974).

         When rabbits were fed 0.5 g/kg bw of the colour the following
    metabolites could be identified in urine over a period of 48 hours:
    total p-aminophenol, 46%; p-aminophenylglucuronide, 37%; aniline, 0.6%
    and o-aminophenol, 9%. The ratio of o-aminophenol to p-aminophenol was
    the same for rabbits fed Red 2G and rabbits fed aniline previously
    examined by Parke (1960) indicating that hydroxylation does not
    necessarily precede fission of the azolinkage.

         No binding of Red 2G to serum protein occurs (Jenkins et al.,
    1966a).

    TOXICOLOGICAL STUDIES

    Special studies on aniline

    Rat

         Aniline dissolved in isotonic saline was administered either
    intravenously to rats under anaesthesia or by stomach tube. Saline was
    administered to control animals. Blood samples from the tail were
    taken at 30-minute intervals at first and then at 60-minute intervals.
    The no-effect dose of aniline was 20 mg/kg bw orally and 10 mg/kg bw
    intravenously (Jenkins et al., 1972).

         Groups of six male and six female rats were fed diets containing
    0.098% aniline and molecular equivalent levels of p-aminophenol and
    phenylhydroxylamine. Methaemoglobinaemia, Heinz bodies and splenic
    enlargement were noted in rats which received either aniline or
    phenylhydroxylamine. The no-effect single oral dose of aniline in rats
    was 20 mg/kg bw (Jenkins et al., 1972).

    Man

         Aniline was administered orally to a volunteer for five days. The
    dose was 10 mg on days 1 and 2 and 25 mg on days 3, 4 and 5. Urine
    samples were tested for urobilinogen, glucose and protein and blood
    tests included, haemoglobin, methaemoglobin, packed cell volume, serum
    transaminases, alkaline phosphatase, thymol turbidity, serum proteins,
    serum bilirubin and the staining for Heinz bodies. None of these tests
    revealed an effect due to the ingestion of aniline, nor could Red 2G
    be detected in the urine (Jenkins et al., 1972).

         Single oral doses of 5 and 15 mg aniline had no effect in 20
    human subjects; doses ranging from 25 to 65 mg significantly increased
    the blood level of methaemoglobin to 2.46% but no Heinz bodies were
    observed. Although human subjects are more sensitive to aniline

    in vivo than rats, the methaemoglobin content of rat blood exposed
    to phenylhydroxylamine in vitro exceeded that of human blood exposed
    to phenylhydroxylamine in vitro. Glucose promoted the production of
    methaemoglobin (Jenkins et al., 1972).

    Special studies on haemotoxicity and haemopoiesis

         Rats were fed 1-1.5 g/kg per day Red 2G for 75 days. The mean
    peak Heinz body level was 80% falling to a maintained level of 30%.
    Internal changes included a moderate though well controlled anaemia,
    pronounced reticulocytosis, and splenomegaly (Rofe, 1957).

         Methaemoglobin and Heinz bodies have been observed in acute human
    aniline poisoning by a number of investigators (Freifield et al.,
    1937; Hughes & Treon, 1954; Rodek & Westhaus, 1952). Methaemoglobin
    formation occurred first followed by Heinz body appearance, the latter
    being an irreversible process, Heinz bodies are formed most in vivo
    but can be studied also in vitro.

         It has been shown that phenylhydroxylamine is the N-hydroxylated
    metabolite which produces most of the methaemoglobin observed in the
    dog after injection of aniline. The reaction probably proceeds by
    oxidation of phenylhydroxylamine to nitrosobenzene by O2 and Hb with
    conversion of Hb to methaemoglobin (Kiese, 1959).

         Since the rat is less susceptible to Heinz body producing agents
    than the cat and possibly man, a procedure was devised which increased
    the sensitivity of the rat to these agents by pretreating rats with
    p-aminopropiophenone, 15 mg/kg bw subcutaneously (Unilever, 1974).
    Methaemoglobinaemia is a reversible response to toxic injury and
    depends on the integrity of the erythrocyte in vivo. Reduction of
    methaemoglobin occurs through an NADH-dependent diaphorase system
    which is deficient in subjects with hereditary mathaemoglobinaemia or
    in young infants.

         The effects of feeding aniline, para-aminophenol and
    phenylhydroxylamine at a level of 0.1% in the diet of rats were
    compared for 13 days. The results indicated that compared with a
    control group, para-aminophenol had no effect on spleen weight,
    aniline increased mean relative spleen weight by about 60% and
    phenylhydroxylamine increased mean relative spleen weight by about
    500%. Examination of the blood after feeding phenylhydroxylamine
    for 11 days revealed a high incidence of Heinz bodies. Therefore,
    the toxic effects of feeding aniline can be attributed to
    phenylhydroxylamine which is a metabolite of aniline (Gellatly &
    Burrough, 1966; Jenkins et al., 1966b).

         Three groups of six four-week old female rats were fed in their
    diet 0, 0.5% Red 2G or 0.093% aniline. All rats were fed ad libitum
    for 19 days. The faeces of rats fed Red 2G were almost black; the
    faeces of rats fed aniline were a normal colour. Both Red 2G and
    aniline caused a similar increase in spleen weight, accelerated
    erythropoiesis and haemosiderin content.

         For rats fed purified diets containing 0. 1, 0.2 and 0.3% Red 2G
    for two weeks there was a linear relationship between intake of Red 2G
    and relative spleen weight. For rats fed purified diets containing
    0.004, 0.006 and 0.012% phenylhydroxylamine for two weeks there was a
    linear relationship between intake of phenylhydroxylamine and relative
    spleen weight (Jenkins et al., 1967; Gellatly & Burrough, 1967).

         For individual samples of rat blood and human blood the amount of
    oxidation of haemoglobin to methaemoglobin was linearly related to the
    logarithm of phenylhydroxylamine concentration. From the dose-response
    curve it has been estimated that for rat blood the no-effect dose is
    between 0.5 and 1 g phenylhydroxylamine/ml blood. The response of
    human blood to phenylhydroxylamine was more variable than the response
    of rat blood. The no-effect concentration of phenylhydroxylamine
    in vitro for human blood ranged from 0.46 to 4.1 g/ml (blood). At
    all levels of Red 2G fed to rats the proportion of Red 2G metabolized
    to phenylhydroxylamine was constant (Unilever, 1974).

         In vitro studies were conducted on samples of mouse, rat and
    human blood with 100 and 200 mg% concentration of Red 2G and
    acetylphenylhydrazine as a positive control. No Heinz bodies were seen
    with Red 2G (BIBRA, 1965).

         Red 2G was fed to male and female Colworth-Wistar rats at dietary
    levels of 0 or 0.5% for two weeks. Some rats from each group were bled
    by cardiac puncture (2 ml from males; 1 ml from females) to stimulate
    erythropoiesis two weeks after administration of Red 2G had ceased. At
    weekly intervals before, during and after feeding Red 2G, three to
    five rats from each group were killed, liver, spleen and kidneys were
    weighed and fixed for microscopic examination. Bone marrow samples
    were taken for differential cell counts and blood samples were
    examined for haemoglobin, methaemoglobin, red cell count, white cell
    count, differential white cell count and PCV. In rats fed Red 2G,
    methaemoglobinaemia, Heinz bodies, reticulocytosis, decreased
    haemoglobin, PCV and red 3 cell count and increased spleen weight were
    observed. In liver, spleen and bone marrow there was an increase in
    erythropoiesis. Rats previously dosed with Red 2G responded to 

    bleeding in a similar manner to controls with increased erythropoiesis
    observed in bone marrow. The results indicated that liver, spleen and
    bone marrow respond to Red 2G with an increase in erythropoiesis but
    there was no evidence that Red 2G had a toxic effect on erythropoiesis
    (Jenkins et al., 1980).

    Special studies on mutagenicity

         In a series of microbial mutagenicity assays, food grade samples
    of Red 2G were shown to possess weak mutagenic activity, inducing
    repairable DNA damage and base-substitution mutations, only after
    metabolic activation with rat-liver microsomes. The products of
    reducing the azo group in Red 2G were non-mutagenic (Haveland-Smith et
    al., 1979; Haveland-Smith & Combes, 1980, 1980a).

    Special studies on reproduction

         Two groups of 46 male and 46 female rats were fed 0.2% Red 2G in
    their diet for 18 weeks and then mated for 10 days. The progeny were
    weaned on the same diet and mated at 16 weeks and the F2 generation
    was also weaned onto the same diet. No adverse effects were seen on
    litter size, litter weight and weaning weight nor were there any
    abnormalities at autopsy (Unilever, 1974).

    Special studies on teratogenicity

         Four groups of 20 female Colworth-Wistar rats were fed diets
    containing 0, 40, 200 or 2000 ppm (0, 0.004, 0.02 or 0.2%) Red 2G on
    days 0-19 of pregnancy (equal to 0, 3.5, 12.9 or 187.5 mg/kg bw per
    day). Fifteen rats from each group were subjected to Caesarian section
    on day 21 of gestation and the foetuses examined for visceral and
    skeletal malformations; dams were examined for corpora lutea,
    implantations and intrauterine deaths. Maternal blood, liver
    and spleen, and foetel bone marrow and spleen were examined
    histologically. Five rats from each group were allowed to litter
    normally and to suckle the pups to weaning at 21 days, when the pups
    were subjected to examination for malformations.

         There was no evidence that Red 2G possessed foeto-toxic or
    teratogenic potential at any of the dose levels studied. Treatment did
    not affect normal parturition or postnatal development to weaning. The
    only significant effect was the expected increase in the spleen weight
    and erythropoietic activity in dams at the top dose level; no effects
    on foetal spleen were observed (Cambridge et al., 1980).

    Acute toxicity
                                                                 

                                   LD50
    Animal         Route         (g/kg bw)         Reference
                                                                 

    Mouse          Oral       7.35               Unilever, 1974

                   i.p.       4.76 (4.13-5.85)   Unilever, 1974

                   i.p.       3.0-4.0            BIBRA, 1965

    Rat            i.p.       6.35 (5.62-7.17)   Unilever, 1965

                   Oral       >5.0               Unilever, 1974

    Guinea-pig     Oral       4.81 (3.16-7.35)   Unilever, 1974

                   i.p.       3.0 (1.83-4.91)    Unilever, 1974

    Rabbit         Oral       >5.0               Unilever, 1974

    Chicken        Oral       >10.0              Unilever, 1974
                                                                 

         No deaths occurred in six weanling rats following administration
    of 5 g/kg bw (Unilever, 1974).

         A dose of 5 g/kg bw was administered on each of two successive
    days to a rabbit weighing 3.8 kg and a dose of 25 g/kg bw was
    administered on each of two successive days to a rabbit weighing
    4.3 kg. No signs of toxicity were observed and their red cells
    contained no Heinz bodies (Unilever, 1974).

         Histological studies in rats, rabbits and guinea-pigs doses as
    given above showed extensive renal necrosis. In mice dosed orally with
    Red 2G there was gross leptomeningeal vascular engorgement and focal
    subarachnoid haemorrhage (Unilever, 1974).

         No deaths occurred in three-week old and nine-week old chickens
    following administration of 10 g/kg bw. There was no evidence of renal
    necrosis (Unilever, 1974).

    Short-term studies

    Mouse

         Five groups of 15 male and 15 female mice were given diets
    containing 0.0, 0.01, 0.1, 1.0 and 2.0% Red 2G. Five mice of each sex
    at each dose level were killed at 26, 55 and 96 days, when a full
    autopsy and haematological investigation was carried out on each
    animal. No adverse effect on growth or food consumption was evident in
    any animal given Red 2G in the diet. Heinz bodies were seen at all
    levels, the incidence being related to dose and duration of treatment.
    The maximal effect was seen on day 26 and day 55 at a level of 0.1%
    and below and on day 26 at 1.0 and 2.0%. Splenomegaly was seen at 2.0%
    in both sexes and at 1.0% in females. Increased relative liver weights
    were found in females at 2.0% throughout the tests and at 1.0% after
    26 days treatment. The only pathological finding attributable to the
    administration of Red 2G was increased haemosiderin in the Kupffer
    cells of the liver at 2.0 and 1.0%. Haemosiderin was also present in
    the spleen at 2.0% throughout the test; at 1.0, 0.1 and 0.01% the
    incidence of haemosiderin increased with the duration and treatment
    (BIBRA, 1965).

         In another study Red 2G was fed for six weeks to five groups
    of 10 mice at dietary levels of 0, 0.02, 0.1, 0.5 and 1.0%. The
    toxic effects observed were development of Heinz bodies,
    methaemoglobinaemia, splenic enlargement, accelerated splenic
    macrophages. No toxic effects were observed in mice fed the diet
    containing 0.02% (Unilever, 1974).

    Rat

         Six groups of five male and five female rats were given diets
    containing 0.0, 0.05, 0.1, 0.5, 1.0 and 2.0% Red 2G for three weeks.
    A further four groups of 10 male and 10 female rats were given diets
    containing 0.0, 0.01, 0.05 and 0.1% Red 2G for two months. Retarded
    growth associated with reduced food consumption was seen at 5.0 and
    2.5% after nine days, with an initial retardation at 2.0%. No
    effect on growth or food consumption was seen at lower levels of
    administration. Macrocytosis, reticulocytosis and polychromasia were
    evident at 5.0% with circulating normoblasts and a normoblastic
    marrow. Heinz bodies were present in animals at 1.0% and above after
    nine days and 1.0 and 0.5% after three weeks exposure. Signs
    indicative of increased erythropoiesis could be seen in animals at all
    levels down to 0.1%. Significant splenomegaly was evident at all
    levels above 0.5% with scattered non-significant increases in spleen
    weight at 1.0 and 0.05% after two months. Increased kidney weight was
    also seen at 0.1% and above. On histological examination the only
    change attributable to Red 2G was the increased haemosiderin seen in
    the Kupffer cells of the liver, renal tubule cells and spleen in all

    animals at 2.0% and in some at 1.0 and 0.5%. Blood samples were taken
    from the tail of the rats. By nine days a definite haemolytic anaemia
    with Heinz body formation was present at all levels from 0.5 to 2.0%
    (BIBRA, 1965).

         Three groups of 12 rats received Red 2G in the drinking-water at
    levels of 0, 0.1 and 0.5% for 100 days. Heinz bodies were seen after
    10 days in the red cells of rats fed 0.5% Red 2G in the drinking-
    water, fewer were seen after 18 days and none or very few on later
    occasions. A few Heinz bodies were occasionally seen in the red cells
    of some of the rats fed 0.1% Red 2G in the drinking-water. The spleens
    of rats fed 0.1% Red 2G were slightly larger than controls and the
    spleen of rats fed 0.5% Red 2G were very much larger than controls.
    Histological examination of livers of rats fed 0.5% Red 2G revealed an
    increase in haemosiderin present in Kupffer cells and increased
    erythropoietic activity. Histological examination of the spleens of
    rats fed 0.5% Red 2G also revealed increased erythropoiesis and red
    pulp engorgement. There was no effect of Red 2G on urine specific
    gravity (Jenkins et al., 1966c; Gellatly et al., 1966).

         Four groups of 24 male and 24 female rats were fed at dietary
    levels of Red 2G which would ensure intakes of 100 x and 600 x the
    assumed average daily dietary intake of Red 2G. This was achieved by
    feeding sausage meat, containing 0, 30 and 180 ppm (0, 0.003 and
    0.018%) Red 2G respectively in the diet at a level of 80%. The diets
    containing Red 2G in sausage meat had no effect on growth, organ
    function or organ weights. Blood tests also revealed no evidence of
    toxicity. Histological examination revealed that, in the spleens of
    rats fed sausage meat containing 180 ppm (0.018%) Red 2G, there was
    increased erythropoiesis, increased splenic red pulp haemosiderin and
    increased red pulp reticular impregnation with iron. No-effects on
    spleen were seen in rats fed sausage meat containing 30 ppm (0.003%)
    of Red 2G. Red 2G at 30 ppm (0.003%) and at 180 ppm (0.018%) in
    sausage meat had no detectable histological effect on liver (Jenkins
    et al., 1966d).

    Long-term studies

    Mouse

         Five groups of 40 male and 40 female mice were fed diets
    containing 0, 0.005, 0.025, 0.125 and 0.625% for 20 months. Splenic
    enlargement and darkening were seen in mice fed dietary levels of
    0.125 and 0.625% of Red 2G; in these animals there was accelerated
    formation of red blood cells in the spleen and increased deposition of
    iron in spleen and kidneys. There was no evidence of carcinogenicity
    attributable to the feeding of Red 2G to mice. More than three-
    quarters of the animals in each group survived for two years
    (Unilever, 1974).

    Rat

         Five groups of 40 male and 40 female rats were fed at dietary
    levels of 0.004, 0.016, 0.064 and 0.16% Red 2G. Rats fed diets
    containing 0.064 and 0.16% of Red 2G showed splenic enlargement and
    darkening attributable to increased storage of iron resulting from
    haemolysis of red blood cells. Necrosis of splenic elastica was also
    identified, this lesion being a sequel to prolonged splenic
    enlargement. There was no evidence of carcinogenicity attributable to
    the feeding of dietary levels of Red 2G up to 0.16% for two years.
    Over half of each group of rats survived for two years (Unilever,
    1974).

         Two groups of 30 male and 30 female rats were fed a diet
    containing 0 or 0.5% Red 2G. At the 0.5% level there was enlargement
    and darkening of the spleen, attributable to accelerated splenic
    erythropoiesis, increases splenic haemosiderin deposition and
    extensive degeneration of splenic elastica. Biochemical studies of
    blood and urine revealed no adverse effects on liver and kidneys which
    could be attributed to feeding 0.5% Red 2G in the diet. More than half
    the animals in the test group survived for two years (Unilever, 1974).

    Comments

         In the in vitro bacterial mutagenicity studies Red 2G only
    induced mutations at very high concentrations of 10 mg/ml; no activity
    was detectable at 1 mg/ml. Microsomal activation was required for
    mutagenic activity and the reduction products of Red 2G were inactive.
    Since Red 2G is substantially reduced by the gut microflora prior to
    absorption (Walker, 1971) the concentrations of the dye reaching the
    tissues (other than the intestinal mucosa) is likely to be very small
    and considerably lower than that required to induce mutations in the
    bacterial studies.

         The teratology study and the study on the effects on
    erythropoiesis were in response to the work required in the
    previous evaluation by JECFA (WHO, 1980).

    EVALUATION

    Level causing no toxicological effect

    Mouse:    0.025% in the diet, equal to 43-26 mg/kg/day for 80 weeks.

    Rat:      0.016% in the diet, equivalent to 8 mg/kg/day for two years.

    Estimate of acceptable daily intake for man

    0-0.1 mg/kg bw.

    FURTHER WORK OR INFORMATION

    Desirable

         Further studies on the mutagenicity of Red 2G and its major
    subsidiary components in a range of test systems in vitro.

    REFERENCES

    BIBRA (1965) Acute and short-term feeding studies on Red 2G with
         associated haematological investigations, British Industrial
         Biological Research Association, Research Report 3/1965.
         Unpublished report submitted to WHO

    Cambridge, G. W. et al. (1980) Teratology study on Red 2G in the
         Colworth Wistar Rat. Unpublished report from Unilever Research
         Laboratories, submitted to WHO by Unilever Ltd.

    Freifield, H., Schilowa, A. & Ludwinowsky, R. (1937) Heinz bodies and
         methaemoglobin formation in poisoning by compounds containing
         amino and nitro groups, Folia Haematol., 56, 333-342

    Gellatly, J. B. M. & Burrough, R. (1966) Effects of diets containing
         aniline and metabolites of aniline on spleen weights; pathology.
         Unpublished report from Unilever Research Laboratories, submitted
         to WHO by Unilever Ltd

    Gellatly, J. B. M. & Burrough, R. (1967) Pathology of Red 2G and
         phenylhydroxylamine in fat diets. Unpublished report from
         Unilever Research Laboratories, submitted to WHO by Unilever Ltd.

    Gellatly, J. B. M., Salmond, G. & Burrough, R. (1966) Sub-acute
         toxicity of Red 2G; pathology. Unpublished report from Unilever
         Research Laboratories, submitted to WHO by Unilever Ltd.

    Haveland-Smith, R. B., Combes, R. D. & Bridges, B. A. (1979)
         Methodology for the testing of food dyes for genotoxic activity:
         Experiments with Red 2G (C.I. 18050), Mut. Res., 64, 241-248

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

    Haveland-Smith, R. B. & Combes, R. D. (1980) Genotoxicity of the food
         colours Red 2G and Brown FK in bacterial systems. Use of
         structurally-related dyes and azo-reduction, Fd. Cosmet.
         Toxicol., 18, 223-228

    Hughes, J. P. & Treon, J. F. (1954) Erythrocytic inclusion bodies in
         the blood of chemical workers, Arch. Hyg. occup. Med., 10,
         192-202

    Jenkins, E. P. et al. (1966) Metabolism of Red 2G by rat liver
         homogenate. Unpublished report from Unilever Research
         Laboratories, submitted to WHO by Unilever Ltd.

    Jenkins, F. P. (1966a) Metabolism of Red 2G (protein binding
         capacity). Unpublished report from Unilever Research
         Laboratories, submitted to WHO by Unilever Ltd.

    Jenkins, F. P. at al. (1966b) Effects of diets containing aniline
         and metabolites of aniline on spleen weights. Unpublished
         report from Unilever Research Laboratories, submitted to WHO by
         Unilever Ltd.

    Jenkins, F. P. et al. (1966c) Sub-acute toxicity of Red 2G.
         Unpublished report from Unilever Research Laboratories, submitted
         to WHO by Unilever Ltd.

    Jenkins, F. P., Salmond, G. & Gellatly, J. B. M. (1966d) Sub-acute
         toxicity of Red 2G in sausage meat. Unpublished report from
         Unilever Research Laboratories, submitted to WHO by Unilever Ltd.

    Jenkins, F. P. et al. (1967) Effect of Red 2G and phenylhydroxylamine
         on spleen weight. Unpublished report from Unilever Research
         Laboratories, submitted to WHO by Unilever Ltd.

    Jenkins, F. P. et al. (1972) The no-effect dose of aniline in human
         subjects and a comparison of aniline toxicity in man and rat,
         Fd. Cosmet. Toxicol., 10, 671-679

    Jenkins, F. P., Kennedy, S. & Williams, T. C. (1980) Erythropoiesis
         in the Colworth Wistar rat fed Red 2G. Unpublished report from
         Unilever Research Laboratories, submitted to WHO by Unilever Ltd.

    Kiese, M. (1959) Significance of the oxidation of aniline to
         nitrosobenzene for the formation of methemoglobin after
         absorption of aniline into the organism, Arch. exp. Path.
         Pharmak., 235, 360-364

    Parke, D. V. (1960) Studies in detoxication 84. The metabolism of 14C
         aniline in the rabbit and other animals, Biochem. J., 77,
         493-503

    Priestley, G. & O'Reilly, W. J. (1966) Protein binding and the
         secretion of some azo dyes in rat bile, J. Pharm. Pharmacol.,
         18, 41-45

    Rodek, H. & Westhaus, H. (1952) Aniline poisoning in nurslings from
         ink and labeling dyes, Arch. Kinderh., 145, 77-90

    Rofe, P. (1957) Azo dyes and Heinz bodies, Brit. J. ind. Med., 14,
         275-280

    Ryan, A. J. & Wright, S. E. (1961) The excretion of some azo dyes
         in rat bile, J. Pharm. Pharmacol., 13, 492-495

    Unilever (1974) Unpublished review of the biological effects of food
         colour Red 2G dated November 1974. Submitted to WHO by Unilever
         Ltd.

    Walker, R. (1971) Personal communication to E. M. den Tonkelaar,
         National Institute of Public Health, Bilthoven, Netherlands

    World Health Organization (1978) Twenty-first report of the Joint
         FAO/WHO Expert Committee on Food Additives, Wld Hlth Org.
         techn. Rep. Ser., No. 617, 94-102

    World Health Organization (1980) Twenty-third report of the Joint
         FAO/WHO Expert Committee on Food Additives, Wld Hlth Org.
         techn. Rep. Ser., No. 648, 84-92
    


    See Also:
       Toxicological Abbreviations
       Red 2G (WHO Food Additives Series 12)
       Red 2G (WHO Food Additives Series 14)
       RED 2G (JECFA Evaluation)