Azo dyes are organic compounds. That contain at least one azo group ―N=N― as part of their molecular structures. Certain that can break down under reductive conditions or through the body’s own enzyme system to release aromatic amines. Only those produced carcinogenic or allergenic aromatic amines are widely concerned
Azo dyes contribute 60-70% of all synthetic dyes used as commercial colorants. That are widely used to treat textiles, leather articles. And also used in industrial paints, printing inks, varnishes, plastics, crayons and other products.
Aromatic amines can migrate from clothing and leather articles and be absorbed through the skin where there is direct and prolonged contact. Certain Azo dyes may undergo in vivo reductive cleavage to carcinogenic aromatic amines. Which leads them to be health-endangering materials and have carcinogenic or mutagenic properties.
REACH Annex XVII
Azo dyes which may release one or more of the 22 aromatic amines in detectable concentrations, above 30ppm(each) in the finished articles or in the dyed components may not be used in textile and leather articles which may come into direct and prolonged contact with the human skin or oral cavity.
GB 18401-2010 China’s National General Safety Technical Code for Textile Products
Azo dyes which may release one or more of the certain 24 aromatic amines in apparel, adornment and household textile are forbidden (Limit ≤ 20 ppm each).
GB 31701-2015 Safety Technical Code for Infants and Children Textile Products
Azo dyes which may release one or more of the certain 24 aromatic amines in infants’ and children’s textile are forbidden (Limit ≤ 20 ppm each).
GB 20400-2006 Limit of Harmful Matters in Leather and Fur
Azo dyes which may release one or more of the certain 23 aromatic amines in detectable concentrations, shall not exceed 30 ppm (each) in leather and fur products in daily use.