Lab technician – azo dye textile testing laboratory

Do You Need an Azo Textile Testing Laboratory?

By: QIMA Mar 12, 2024

Under the EU's strict REACH regulations, products containing synthetic dyes must be evaluated by an azo textile testing laboratory to ensure the colorants are safe for consumers.

The legislation currently lists 22 regulated azo dyes or azo colorants that can potentially release hazardous chemicals (aromatic amines) when products containing them are used, disposed of, or recycled.

The azo directives aim to protect workers, consumers and the environment from exposure to the carcinogenic aromatic amines, some of which are known to cause cancer and pose other serious health risks if exposed to the skin, ingested or released into the environment.

Products regulated by azo directives

The REACH (Registration, Evaluation, Authorisation, and Restriction of Chemicals) regulations cover a wide range of products that must be rigorously tested to EU standards before being approved for manufacture or sale in the European Union. These include:

Commercial use of azo dyes and aromatic anilines

The azo colorants on the EU's REACH watchlist are nitrogen-based dyes classified as anilines. Aniline yellow, for example, is used in pyrotechnics, coloured smoke, yellow pigments and inks, insecticides, lacquers, varnishes, waxes, oil stains, and styrene resins.

Anilines are derivatives of organic compounds (aromatic amine) with the formula C6H5NH2. They are inexpensive and widely used in the manufacture of precursors to other industrial chemicals.

These substances are highly volatile, ignite easily, and produce a strong odor of rotten fish.

Due to the dangers posed by these chemicals to consumers and the environment, their manufacture and use in consumer products is strictly regulated and monitored by the EU, as well as by regulatory agencies in the US, Canada and Asia.

Toxic azo derivatives restricted by REACH

The aromatic amines listed below are substances restricted in Appendix 8 of Annex XVII to REACH, adopted from the initial directive 76/769/EEC.

The current maximum detectable limit stipulated for these substances or groups contained in AZO dyes is 30 mg/kg (0.003 % by weight).

AROMATIC AMINES (toxic substances)

  1. biphenyl-4-ylamine; 4-aminobiphenyl xenylamine

  2. benzidine

  3. 4-chloro-o-toluidine

  4. 2-naphthylamine

  5. o-aminoazotoluene; 4-amino-2',3-dimethylazobenzene; 4-o-tolylazo-o-toluidine

  6. 5-nitro-o-toluidine

  7. 4-chloroaniline

  8. 4-methoxy-m-phenylenediamine

  9. 4,4'-methylenedianiline; 4,4'-diaminodiphenylmethane

  10. 3,3'-dichlorobenzidine; 3,3'-dichlorobiphenyl-4,4'-ylenediamine

  11. 3,3'-dimethoxybenzidine; o-dianisidine

  12. 3,3'-dimethylbenzidine; 4,4'-bi-o-toluidin

  13. 4,4'-methylenedi-o-toluidine

  14. 6-methoxy-m-toluidine p-cresidine

  15. 4,4'-methylene-bis-(2-chloro-aniline); 2,2'-dichloro-4,4'-methylene-dianiline

  16. 4,4'-oxydianiline

  17. 4,4'-thiodianiline

  18. o-toluidine; 2-aminotoluene

  19. 4-methyl-m-phenylenediamine

  20. 2,4,5-trimethylaniline

  21. o-anisidine; 2-methoxyaniline

  22. 4-amino azobenzene

New EU standard azo textile testing requirements introduced

(EN ISO 14362-1:2017)

Changes were made by the European Committee for Standardization (CEN) in 2017 to improve the accuracy of laboratory testing methods to detect aromatic amines from azo dyes in man-made fibers and imitation leather.

Synthetic fabrics must now go through a chemical extraction process before reductive cleavage, whereas natural fibers such as cotton, wool, and silk can be cleaved directly.

The extraction solvent xylene replaces chlorobenzene as it poses fewer health risks.

A special procedure to detect 4-aminoazobenzene (solvent yellow 1) has also been added.

How can QIMA help you?

QIMA has fully accredited azo textile testing laboratory facilities qualified to evaluate all textiles and leather goods in accordance with the latest EU quality control standards set out in the azo directives for REACH certification.

We provide a comprehensive range of transparent testing services worldwide, and industry-leading turnaround time so you can get answers quickly. Contact us here to receive an instant quote for our professional services.

Related Articles