Chronic Toxicity Studies on Food Colours: V. Observations on the Toxicity of Brilliant Blue FCF, Guinea Green B and Benzyl Violet 4B in Rats

Abstract

The food colours Brilliant Blue FCF, Guinea Green B and Benzyl Violet 4B were fed to rats at concentrations of 0.03, 0.3 and 3 per cent of the diet for 75 weeks. Thirty rats were used at each feeding level. Brilliant Blue and Benzyl Violet had no adverse effects on growth at any of the levels used. With Guinea Green there was an initial depression of growth at the two higher levels accompanied by a decreased food efficiency and, in one group, a lower food consumption. There was an increase in mortality in female rats fed 3 per cent of all three colours. With Brilliant Blue, indications were that this increase was not related to treatment. In the groups fed 3 per cent Guinea Green and 3 per cent Benzyl Violet there was a total of eight malignant tumours. Five of these were derived from the epidermis. Further investigation of these two colours is required.