Toxicity Profile for Indigo carmine (1995)

Abstract

A small number of individuals have been reported to respond adversely to orally administered indigo carmine, typically with skin complaints. Indigo carmine is possibly a weak local sensitizer. A case of occupational asthma has also been reported. The main adverse effects of injected indigo carmine to humans involve the cardiovascular system. Indigo carmine was slightly irritating to the eyes of rabbits. A low acute oral toxicity was indicated in rodents, whilst anaemia has been seen in mice and pigs subject to repeated oral exposure. Western studies provided no convincing adverse reproductive effects in rats or rabbits. Long-term oral studies in rats and mice generated no clear indication of any carcinogenic potential. Chromosome effects occurred in mice given indigo carmine orally. Oral administration to male rats gave no evidence of (dominant lethal) mutations although mutagenicity was observed in mammalian cells in culture. Studies of mutagenic potential in the bacterium Salmonella typhimurium (Ames tests) have given uniformly negative results.