Azo-free
Made with synthetic dyes that do not break down into certain banned chemicals, a standard for safe colour.
Also: azo free dyes
Azo dyes are a large family of synthetic dyes. A few of them can release certain aromatic amines, which are chemicals thought to be harmful, and several countries including those of the European Union restrict them in cloth that touches the skin. Azo-free means a fabric has been dyed without those restricted dyes. It does not mean the cloth is natural dyed. Many handloom cooperatives and export buyers ask for azo-free dyeing, and it is a useful claim to look for on a label, ideally with a test report behind it.