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    INTERNATIONAL PROGRAMME ON CHEMICAL SAFETY

    WORLD HEALTH ORGANIZATION



    TOXICOLOGICAL EVALUATION OF SOME
    FOOD COLOURS, ENZYMES, FLAVOUR
    ENHANCERS, THICKENING AGENTS, AND
    CERTAIN FOOD ADDITIVES



    WHO FOOD ADDITIVES SERIES 6







    The evaluations contained in this publication were prepared by the
    Joint FAO/WHO Expert Committee on Food Additives which met in Rome,
    4-13 June 19741


    World Health Organization     Geneva     1975






              

    1  Eighteenth Report of the Joint FAO/WHO Expert Committee on
    Food Additives, Wld Hlth Org. techn. Rep. Ser., 1974, No. 557.
    FAO Nutrition Meetings Report Series, 1974, No. 54.

    GLYCEROL ESTERS OF WOOD ROSIN*

    BIOLOGICAL DATA

    BIOCHEMICAL ASPECTS

         No information.

    TOXICOLOGICAL STUDIES

    Acute toxicity
                                                                        

                               LD50 mg/kg bw
    Substance    Route                                   References
                         Rats     Mice     Guinea-pigs
                                                                        

    Pale gum     Oral    7 600    4 600    4 100         Anonymous, 1974
    rosin

    Pale wood    Oral    8 400    4 100    4 100         "          "
    rosin

    Pale tall    Oral    7 600    4 600    4 600         "          "
    oil rosin
                                                                        

    Short-term studies

    Rat

    (a)  Gum rosin

         Groups of 10 male and 10 female rats were fed dietary levels of
    0.01, 0.05, 0.2, 1.0 and 5.0% for 90 days. Two similar groups received
    the stock diet only. No effects were seen upon growth, food intake,

              

    *    The natural product rosin is a complex mixture of mutually
    soluble organic compounds. There are three general methods of
    producing rosins commercially, these methods (and their products)
    being: solvent extraction of pure stump wood (wood rosin); tapping of
    gum from the living tree (gum rosin); separation from tall oil (tall
    oil rosin). The three rosins, freed of extraneous impurities and
    refined, differ somewhat quantitatively and in colour but all three
    may be glycinerated to produce the glycerol ester.

    haematology, urinalysis, gross and microscopic histology at levels
    through 0.2%. At the 5% feeding level all animals died. At 1% the test
    animals showed an initial lag in weight gain and food consumption
    during the first two weeks, and liver size was increased at autopsy,
    no microscopic pathology being seen however (Anonymous, 1960a).

    (b)  Wood rosin

         A study was carried out following a protocol similar to that for
    gum rosin (see (a) above). Results obtained were similar to those seen
    for gum rosin (Anonymous, 1960b)

    (c)  Tall oil rosin

         A study was carried out following a protocol similar to that for
    gum rosin (see (a) above). Results obtained were similar for those
    seen for gum rosin (Anonymous, 1960c)

    (d)  Glycerin ester of wood rosin

         A study was carried out following a protocol similar to that for
    gum rosin (see (a) above) using a Hercules product, Ester Gum 8D. No
    effects were noted upon growth, food intake, haematology, urinalysis,
    gross and microscopic histology at dietary levels up to and including
    1%. At the 5% level depressant effect on growth and food intake was
    evident and there was a suggestion of increased liver size. No
    microscopic pathology was seen (Anonymous, 1960d).

    Long-term studies

    Rat

    (a)  Gum rosin

         Groups of 30 male and 30 female rats were fed dietary levels of
    0.05, 0.2 and 1.0% for two years. Two similar control groups received
    the stock diet only. At the 0.05% and 0.2% feeding levels no effects
    were seen upon weight gain, food consumption, mortality, haematology
    and gross and microscopic pathology. At the 1% dietary level some
    growth depression was noted and at autopsy liver size was increased
    although no microscopic pathology was noted (Anonymous, 1962d).

    (b)  Wood rosin

         A study was carried out following a protocol similar to that for
    gum rosin (see (a) above). Results obtained were similar to those seen
    for gum rosin (Anonymous, 1962e)

    (c)  Tall oil rosin

         A study was carried out following a protocol similar to that for
    gum rosin (see (a) above). Results obtained were similar to those seen
    for gum rosin (Anonymous, 1962f).

    Dogs

    (a)  Gum rosin

         Groups of three male and three female dogs were fed dietary
    levels of 0.5 and 1.0 for two years. A control group consisting of six
    animals of each sex received the basal diet. At the 0.05% level no
    effects were seen upon weight, food consumption, mortality,
    haematology, urinalysis, liver and kidney function tests, gross and
    microscopic histopathology. At the 1% level some increase in liver and
    kidney size was noted although no pathology was present (Anonymous,
    1962a).

    (b)  Wood rosin

         A study was carried out following a protocol similar to that for
    gum rosin (see (a) above). Results obtained were similar for those
    seen for gum rosin (Anonymous, 1960b).

    (c)  Tall oil rosin

         A study was carried out following a protocol similar to that for
    gum rosin (see (a) above). Results obtained were similar to those seen
    for gum rosin (Anonymous, 1962c).

    Comments:

         The basic rosins used for production of the glycerol esters are
    gum rosin, wood rosin and tall oil rosin. Various modifications of
    these rosins are also used for esterification but not included for
    evaluation in this monograph. Levels of 0.05%, 0.2%, and 1% in the
    diet of all basic rosins have been tested adequately in 90 days and
    two year studies in the rat. The effects noted were essentially growth
    reduction and increased liver weight without, however, any reported
    indication of related histopathology. The no-effect level was 0.2%.
    The two year studies in dogs at dietary levels of 0.05 and 1.0% show
    that this species reacts in a manner similarly to the rat.  In dogs
    the effect reported for the 1% level was increased liver weight
    accompanying pathology. A 90 days' rat feeding study using a glycerol
    ester of wood rosin indicates that this ester is qualitatively similar
    in effect to the parent rosin and suggests a lesser degree of
    toxicity.

         With proper definition of the glycerol ester, the long-term
    studies with the parent rosins and the cross-over study with the
    glycerol ester of wood rosin would permit an evaluation.

    EVALUATION

         It was not possible to arrive at an ADI because of absence of a
    specification distinguishing glycerol esters of wood rosin from
    glycerol esters of other rosins.

    REFERENCES

    Anonymous (1960a) Unpublished report from Industrial BioTest
         Laboratories submitted by Hercules Powder Co.

    Anonymous (1960b) Unpublished report from Industrial BioTest
         Laboratories submitted by Hercules Powder Co.

    Anonymous (1960c) Unpublished report from Industrial BioTest
         Laboratories submitted by Hercules Powder Co.

    Anonymous (1962a) Unpublished report from Industrial BioTest
         Laboratories submitted by Hercules Powder Co.

    Anonymous (1962b) Unpublished report from Industrial BioTest
         Laboratories submitted by Hercules Powder Co.

    Anonymous (1962c) Unpublished report from Industrial BioTest
         Laboratories submitted by Hercules Powder Co.

    Anonymous (1962d) Unpublished report from Industrial BioTest
         Laboratories submitted by Hercules Powder Co.

    Anonymous (1962e) Unpublished report from Industrial BioTest
         Laboratories submitted by Hercules Powder Co.

    Anonymous (1962f) Unpublished report from Industrial BioTest
         Laboratories submitted by Hercules Powder Co.

    Anonymous (1974) Unpublished report submitted by Hercules Powder Co.


    See Also:
       Toxicological Abbreviations