Analysis of safety standards for home textiles - azo dyes

“Are all azo dyes carcinogenic?”

“Most azo dyes are safe, and the only toxic ones are decomposable carcinogenic aromatic amine dyes.”

Azo dyes are dyes that contain at least one azo group (-N=N-) in their chemical structure formula, and are the most varied and widely used class of synthetic dyes. Depending on the number of azo groups they contain, they can be categorized as monoazo, diazo and polyazo dyes. At present, about 2/3 of the commercial synthetic dyes circulating in the market are based on the azo structure, and the widely used direct dyes, acid dyes, reactive dyes, disperse dyes and condensation dyes, etc. may contain the azo structure. Azo is the substance that forms the base color in dyes, and if the azo structure is discarded, then most of the base color of dyes will not be produced.

Typical structure of △Azo dyes

Azo dyes have a wide range of chromatograms, including red, orange, yellow, blue, violet, black, etc. They have a complete range of colors, good color light, and a certain degree of fastness. Therefore, they are widely used in dyeing and printing of many kinds of natural and synthetic fibers, as well as for coloring paints, plastics and rubber. It is also a kind of synthetic material that is most used in the printing and dyeing process of textiles and garments.

△Azo dyes themselves are not carcinogenic.

The so-called carcinogenicity problem is that people have proved after long-term research and clinical tests that the aromatic amines that can be reduced in some azo dyes are potentially carcinogenic to human beings or animals. Some of the azo dyes on textiles will be transferred from textiles to human skin under certain special conditions in the long-term contact with skin, especially when the dyeing fastness is not good, forming harmful components absorbed by the skin and spreading in the human body, and then mixing with the substances released in the process of normal metabolism of the human body, and then undergoing the reduction reaction, altering the structure of the human body's DNA, causing lesions and inducing malignant tumor substances, leading to bladder cancer, ureter cancer, renal pelvis cancer and other malignant diseases. These aromatic amines have been included in the blacklist of banned substances by some countries or organizations.