Friday, January 30, 2009

What is Azo dyes?

Azo Dyes are the major colourants in the textile industry. It allows colours with outstanding colorfastness and wide huge spectrum. However, these dyes may split off aromatic amines and some of them are proven carcinogenic (eg. Benzidine)

* where: (1) Azo dye, (2) Original di-azo-components, (3) Linking component with additional amine.

Regulation / Requirement
According to the directive 2002/61/EC, in textile and leather articles that may come into direct and prolonged contact with human skin or oral cavity, the use of azo colourants, which may release 22 banned listed carcinogenic amines.

Testing Methods
- General Textiles: EN14362-1 (=64 LFGB 82.02-2)
- Polyester: EN14362-2 (=64 LFGB 82.02-4)
- Leather: ISO/TS17234 (=64 LFGB 82.02-3)
- Determination of 4-aminoazobenzene (4-AAB) (=64 LFGB 82.02-9)

Max. 30ppm (each amine)

* In some cases, some clients may set the requirement to 24 banned listed amines or 20ppm. Please kindly contact your testing service provider for solution.