Long-term toxicity studies of chocolate brown HT in mice.

Groups of 48 male and 48 female mice were given diets containing 0 (control), 0.01, 0.1 or 0.5% Chocolate Brown HT for 80 weeks. There was a slightly reduced body weight gain and a lower heart weight in males given the highest dietary level. At the same level at week 77 the packed cell volume and total leucocyte count values in females were lower than those of the controls. However, the relationship of these findings to the treatment was questionable, as was the increased incidence of leucocytic infiltration of the liver in the female mice at the 0.5% level of treatment. A brown coloration of internal organs seen at the highest treatment level was due probably to the Chocolate Brown HT. The distribution of tumours was similar in all groups and it was concluded that there was no evidence of a carcinogenic effect with doses up to 700 mg/kg/day while the no-untoward-effect level was greater than 140 mg/kg/day.