Rhodamine B and Metanil Yellow are 2 non edible dyestuff which are widely used for coloring snacks and drinks in Jakarta. These substances are reportedly toxic for human beings, however no data on the acute or chronic intoxications are available so far.

Groups of mice and rats were fed with either Rhodamine B or Metanil Yellow.The doses of these dyestuffs varied from 0,5 mg to 1350 mg per kilogram body weight. These animals were divided into 3 different experimental groups, respectively acute, subacute and chronic toxicity tests.

Clinical signs included discoloration of the skin and its intensity depend upon the concentration of the dyestuffs used. The body weight gain of the test animals were consistently lower than those of the controls. Some animals became aggressive and canibalism accrued. Pathological lesions consisted of unthriftiness, focal liver inflammation, hydronephrosis, hepatoma and lymphoma.

Considering the results of the experiments, it is justified to warn that the wide use of Rhodamine B and Metanil Yellow for food coloring, which might be hazardous for human health.