Sudan III Dyes

Sudan dyes is a chemical stain, not a food additive. Its chemical composition contains a compound called naphthalene, which has an azo structure. Due to the nature of this chemical structure, it is carcinogenic and has a significant toxic effect on human liver and kidney organs. Sudan red is a chemical dye, mainly used in petroleum, motor oil and some other industrial solvents, in order to enhance its color, but also used in shoes, flooring, etc. Sudan red is a lipophilic azo dye, mainly used for dyeing oil paint, motor oil, wax and shoe polish. Because the color of the food dyed with Sudan Red is very bright and not easy to fade, it can cause a strong appetite. Some illegal food companies have added Sudan Red to food.

Sudan III Dyes Figure 1. Chemical structure of Sudan Red.

Sudan III Dyes

IARC classified Sudan Red III as a third-class carcinogen, but its primary metabolite, 4-aminoazobenzene, was classified as a second-class carcinogen, which may be a carcinogen for humans. Animal tests showed that rats were given 4-aminoazobenzene for 104 weeks at a dose of 80-400 mg / kg, and the incidence of liver cancer in rats increased significantly. If the maximum daily intake of Sudan Red III in the human body is 1750 μg, theoretically it will reduce to produce 979 μg of 4-aminoazobenzene, which is equivalent to 16.3 μg/kg of human body daily.

Sudan III Dyes Figure 2. Chemical structure of Sudan III.

Applications

It is used to color non-polar substances such as oils, fats, waxes, greases, various hydrocarbon products and acrylic emulsions. Its main use is as a fuel dye commissioned by the Internal Revenue Service (IRS) to distinguish between low-tax heating oil and automotive diesel fuel, and it is marked by the U.S. Environmental Protection Agency (EPA) for higher sulfur Content; it is an alternative to Solvent Red 26 and has higher solubility in hydrocarbons. The concentration required by IRS is equivalent to solvent red 26 in solid form, which is equivalent to 3.9 pounds per 1,000 barrels or the spectral equivalent of 11.13 mg/l; the concentration required by EPA is about 5 times lower.

Biological staining

Sudan III is a dye used for Sudan staining. Similar dyes include Oil Red O, Sudan IV, and Sudan Black B. They are used for staining of triglycerides in frozen sections, and some protein bound lipids and lipoproteins on paraffin sections. It has the appearance of brown crystals and a maximum absorption at 507(304) nm.

Safety

Inhalation or swallowing of Sudan III is harmful and can be absorbed through the skin. MSDS has a severity rating of 3 and cannot be made non-toxic. Inhalation can cause poisoning, and eye contact can cause blurred vision and potential blindness. Toxic to the nervous system, especially the optic nerve. Once absorbed into the body, it disappears very slowly. Symptoms of overexposure may include headache, drowsiness, nausea, vomiting, blurred vision, blindness, coma, and death.