CI 19140 Acid Yellow 23 is a pervasive azo dye used in many fields and is potentially harmful to the environment and human health. This document has studied its toxic effects on trypsin with docking and molecular spectroscopic methods (1).

Another problem related not only to this dye, but also to many other azo dyes, is the decontamination of waste water from production (2).

References_____________________________________________

(1) Toxic interaction between acid yellow 23 and trypsin: spectroscopic methods coupled with molecular docking.
Wang J, Liu R, Qin P.
J Biochem Mol Toxicol. 2012 Sep
(2) Decolorization of C.I. Acid Yellow 23 solution by electrocoagulation process: investigation of operational parameters and evaluation of specific electrical energy consumption (SEEC).
Daneshvar N, Khataee AR, Amani Ghadim AR, Rasoulifard MH.
J Hazard Mater. 2007 Sep

CI 19140 Yellow 5 or Acid Yellow 23 or Tartrazine, is a synthetic chemical product, an azo derivative used mainly in the food and cosmetic fields.

Description of the raw materials used in its production.

Aniline. An organic compound used as a starting point in the synthesis of many azo dyes.

Sulfuric and nitric acid. Used for the nitration of aniline.

Hydrochloric acid. Used in the formation of the diazonium salt.

Tartaric acid. Reacts with the diazonium salt to form Tartrazine.

Step-by-step summary of its industrial chemical synthesis process.

• Nitration of aniline using sulfuric and nitric acid to form 4-nitroaniline.
• The 4-nitroaniline is then reduced to 4-aminoaniline.
• The 4-aminoaniline is converted into a diazonium salt using hydrochloric acid and sodium nitrite.
• The diazonium salt reacts with tartaric acid to form Acid Yellow 23 or Tartrazine.
• The product is then purified and isolated for use as a dye.

What it is for and where

It is an ingredient whose primary function is to colour the solution in which it is inserted in a temporary, semi-permanent or permanent manner, either alone or in the presence of complementary components added for colouration.

It occurs in the form of a yellow powder.

Cosmetics

It is a restricted ingredient as IV/44 (CI 19140) III/189 (Acid Yellow 23; Acid Yellow 23 Aluminum lake)  a Relevant Item in the Annexes of the European Cosmetics Regulation 1223/2009. Substance or ingredient reported: Trisodium 5-hydroxy-1-(4-sulphophenyl)-4-((4-sulphophenyl)azo)pyrazole-3-carboxylate and its insoluble barium, strontium and zirconium lakes, salts and pigments.

Colorant. This ingredient has the function of colouring the solution in which it is inserted in a temporary, semi-permanent or permanent manner, either alone or in the presence of the complementary components added for colouring.

Hair dyeing. It is an ingredient that adds a colouring to the hair that can be temporary, semi-permanent or permanent depending on what other ingredients are added to achieve the result. The pH for hair dyeing is generally between 9 and 10.

Safety. The problem with azo dyes (monoazo or diazo) is photocatalytic degradation leading to oxidation and subsequent formation of impurities such as aromatic amines, some of which have carcinogenic activity.

CI 19140  studies

• Molecular Formula   C₁₆H₉N₄Na₃O₉S₂
• Molecular Weight   534.36 g/mol
• CAS  1934-21-0
• EC number   217-699-5

Synonyms:

• Tartrazine
• Food Yellow 4
• 1310yellow