Chocolate Brown HT was given in the diet to groups of 3 male and 3 female pigs at dose levels of 0 (control), 5, 20 or 100 mg/kg/day for 13 weeks. No adverse effects were seen on body weight gain, urine composition of the incidence of histopathological lesions. The haemoglobin levels in all 3 treatment groups of male pigs at week 13 were significantly below the control values, but this effect was not considered to be attributable to treatment with Chocolate Brown HT. The no-untoward-effect level in this study was at least 100 mg/kg/day.