INTERNATIONAL PROGRAMME ON CHEMICAL SAFETY

    WORLD HEALTH ORGANIZATION



    SUMMARY OF TOXICOLOGICAL DATA OF CERTAIN FOOD ADDITIVES
    AND CONTAMINANTS



    WHO FOOD ADDITIVES SERIES NO. 13






    The data contained in this document were examined by the
    Joint FAO/WHO Expert Committee on Food Additives*
    Rome, 3-12 April 1978




    Food and Agriculture Organization of the United Nations
    World Health Organization



    * Twenty-second Report of the Joint FAO/WHO Expert Committee on Food
    Additives, Geneva, 1978, WHO Technical Report Series No. 631

    STANNOUS CHLORIDE

    Explanation

         Stannous chloride was evaluated at the 1972 Joint FAO/WHO Expert
    Committee on Food Additives.The following additional studies have been
    provided.

    Special studies

    Rat

         Groups of eight male rats weighing approximately 250 g were
    fasted for 17 hours after which a 50 mg/kg dose of Sn113Cl2
    (0.5 µCi/mg tin) was administered by gavage in either: (1) water; (2)
    sucrose at 5 g/kg bw; (3) ascorbic acid at 0.5 g/kg bw; (4) potassium
    nitrate at O.1 g/kg bw; (5) a mixture of all three compounds; (6) 20%
    alcohol solution; (7) a solution of albumin at 2.5 g/kg bw; or (8)
    1:1 (v/v) sunflower oil - 1% Tween 20 emulsion at 10 ml/kg. Rats were
    placed in metabolic cages, fasted for another six hours and then
    received a basal diet ad libitum. Urine and faeces were collected
    from 0-24 and 24-48 hours. Animals were then sacrificed, excreta and
    selected organs and tissues analysed for radioactivity. In all groups
    90-99% of the administered dose was excreted in the faeces within 48
    hours. Only traces of Sn113 were detected in the urine and the organs
    and tissues examined (Fritsch et al., 1976).

         Two groups of 10 young male rats were fed diets containing 0 and
    5000 ppm, approximately 1500 mg/kg bw, stannous chloride for one
    month. Each test animal received daily radioactive Sn113Cl2
    (2 µCi/day) in an HCl/KCl solution. Control animals received the
    carrier only. Two additional groups of rats were fed as described for
    one month. These animals were used for histological examination of
    various organs and tissues. Body weight and food consumption were
    depressed. Food efficiency, protein efficiency and nitrogen balance
    were within normal limits. Ninety-nine per cent. of the administered
    labelled tin was excreted in the faeces and less than 1% in the urine.
    The radioactivity in the gastrointestinal tract, organs and carcass
    was negligible. The treated animals developed anaemia characterized by
    a significant drop in haemoglobin and haematocrit values. Relative
    weights of the liver, spleen and kidney were increased. Histological
    examination of the treated animals revealed a marked congestion of the
    kidneys and cortex of the adrenals. There was also congestion,
    desquamation of the mucosa in the upper gastrointestinal tract from
    the stomach to ileum (Fritsch et al., 1977a).

    Short-term studies

    Rat

         Groups of young male rats (50 g) were fed a basal diet
    supplemented with 0, 4000 or 8000 ppm (0, 200 or 400 mg/kg bw)
    stannous chloride for six months. During the last two weeks of the
    study each treated animal received 2 µCi Sn113Cl2 daily by gavage.
    Control animals received only the Hcl/Kcl carrier. Three additional
    groups each consisting of five rats were fed as above and were used
    for histological examination. Body weights of the treated animals were
    depressed. Food consumption was decreased during the first eight weeks
    of the study. The peri-epididymal fat tissue, haemoglobin, haematocrit
    and serum iron were decreased in both test groups. Relative weights of
    the testes, heart and brain in the low level group and spleen, adrenal
    kidney, testes, seminal vesicle, heart and brain in the high dose
    group, were increased. Histological examination revealed a marked
    atrophy of the exocrine pancreas, interstitial oedema in the kidneys
    and adrenal. The gastrointestinal tract, from the stomach to lower
    ileum, showed signs characteristic of irritation, oedema, congestion
    of the mucosa with accumulation of mucus (Fritsch et al., 1977b).

    REFERENCES

    Fritsch, P., de Saint Blanquat, G. and Derache, R. (1976) Effect of
    various dietary components on absorption and tissue distribution of
    orally administered inorganic tin in rats, Food Cosmet. Toxicol.,
    15, 147

    Fritsch, P., de Saint Blanquat, G. and Derache, R. (1977a) Etude
    nutritionelle et toxicologique, chez le rat, d'un contaminant
    alimentaire: l'étain, Toxicology, 8, 165

    Fritsch, P., de Saint Blanquat, G. and Derache, R. (1977b) Impacts
    nutritionels et toxicologiques de l'étain inorganique administré
    pendant 6 mois chez le rat. Unpublished data

    See Also:
       Toxicological Abbreviations
       STANNOUS CHLORIDE (JECFA Evaluation)