Toxicology of indigo. A review.

Most reports relating to the biological and toxicological properties of indigo have never been published in scientific journals. They are in the files of commercial testing laboratories, government agencies or sponsoring industrial corporations. They include studies of acute oral, dermal and inhalation toxicity, subchronic and chronic dietary effects in the rat and dog, multi-generation and dose-response effects, repeated dermal applications, human skin sensitization, and end-use in surgical sutures for the eye. This review summarizes the experimental protocols and results of these studies and others reported in the literature. It is concluded that indigo has a very low order of both acute and chronic toxicity.