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