Table 1.

Structures, Application, and Possible Carcinogenicity of Sudan Azo Dyes [3, 32, 35, 39, 42]

Structure	Application	Carcinogenesis
Sudan I	Coloring solvents, oils, waxes, petrol, printing inks, and shoe.	Liver and urinary bladder carcinogen in mammals and is considered a possible human mutagen.
Para Red	Coloring solvents, oils, waxes, petrol, printing inks, and shoe.	Toxicology not fully investigated. It would be prudent to assume that it, like Sudan I, could be a genotoxic carcinogen.
Sudan II	Coloring solvents, oils, waxes, petrol, printing inks, and shoe.	Tested in mice by bladder implantation, resulting in a high incidence of bladder carcinomas.
Sudan III	Externally applied drugs and cosmetics. Used for demonstrating the presence of triglycerides in frozen sections.	Studies were inadequate for evaluation.
Sudan IV	Used for demonstrating the presence of triglycerides in frozen sections and commonly for coloring waxes, oils and spirit varnishes.	Tests on laboratory animals indicate it may be mutagenic.