However, indigo carmine is considered a highly toxic indigoid
class of dye and its touch can cause skin and eye irritations to
human beings. It can also cause permanent injury to cornea and
conjunctiva. The consumption of the dye can also prove fatal, as it
is carcinogenic in nature and can lead to reproductive, developmental,
neuro and acute toxicity. It has also been established that the dye
leads to tumors at the site of application[6,7]. Indigo carmine causes
irritation to the gastrointestinal tract leading to nausea, vomiting
and diarrhea. It may also cause irritation to the respiratory tract.
Symptoms may include coughing and shortness of breath