What are Azo Dyes?
Azo dyes are the major colourants used in the textile industry, allowing for a large spectrum of colours and increased colour fastness. They are a large group of synthetic organic dyes that contain Nitrogen as the azo group.
What are the risks of Azo Dyes?
Azo dyes contain one or more nitrogen-nitrogen double bonds called azo groups, under reductive conditions these azo groups can be cleaved to form primary aromatic amines, which are known carcinogens.
Where are Azo Dyes found?
Azo dyes are part of our everyday life; they are used widely in substrates such as textile fibres, leathers, plastics, papers, hair mineral oils, waxes, foodstuffs and cosmetics.
What legislation relates to Azo dyes?
Textiles and leather products (that come into contact with the skin) imported into the EU are not allowed to contain azo dyes which release certain aromatic amines. This is laid down in Annex XVII of REACH.
Azo dyes are covered by the EU directive 2002/61/EC which contains a table list of 24 aromatic amines and consumer goods containing azo dyes that, by reductive cleavage of one or more azo groups may release one or more of the aromatic amines listed in the Table are forbidden.
Azo dyes are also covered in product specific regulations such as EN71 parts 9, 10 & 11 (Toy Directive).
What are the limits for Azo Dyes?
The detectable concentrations of any amine should not exceed 30 ppm in the finished articles or in the dyed parts thereof.
Which products do need to be test for azo dyes:
Clothing, bedding, towel, hairpiece, cap, diaper and other textiles;
Shoe, glove, watch guard, reticule, various purse, brief case, chair cover;
Toys of clothing with textile or leather, synthetic dyes, organic dyes;
Textile and yarn customers finally use.
Any product within the above scope needs to test aromatic amines content which banned azo dyes releases, that is the content of the following 24 kinds of the aromatic amines released in the one and single color material in one test.
The names of these 24 kinds of azo dyes are:
| English Name | Chinese Name |
CAS No. |
4-Aninobiphenyl |
4-氨基联苯 |
92-67-1 |
Benzidine |
联苯胺 |
92-87-5 |
4-Chloro-o-toluidine |
4-氯-邻甲基胺 |
95-69-2 |
2-Naphthylamine |
2-萘胺 |
91-59-8 |
o-Aminoazotoluene |
邻氨基偶氮甲苯 |
97-56-3 |
2-Amino-4-nitrotoluene |
2-氨基-4-硝基甲苯 |
99-55-8 |
p-Chloroaniline |
对氯苯胺 |
106-47-8 |
2，4-Diaminoanisole |
2，4-二氨基苯甲醚 |
615-05-4 |
4，4’-Diaminobiphenylmethane |
4，4’-二氨基二苯甲烷 |
101-77-9 |
3，3’-Dichlorobenzidine |
3，3’-二氯联苯胺 |
91-94-1 |
3，3’-Dmethoxybenzidine |
3，3’-二甲氧基联苯胺 |
119-90-4 |
3，3’-Dimethylbenzidine |
3，3’-二甲基联苯胺 |
119-93-7 |
3，3’-Dimethyl-4，4- diaminobiphenylmethane |
3，3’-二甲基-4，4-二氨基二苯甲烷 |
838-88-0 |
p-Cresidine |
2-甲氧基-5-甲基苯胺 |
120-71-8 |
4，4’-Methylene-bis-（2-chloroaniline） |
4，4’-亚甲基-二-（2-氯苯胺） |
101-214-4 |
4，4’-Oxydianiline |
4，4’-二氨基联苯醚 |
101-80-4 |
4，4’-Thiodianiline |
4，4’-二氨基二苯硫醚 |
139-65-1 |
o-Toluidine |
邻甲基苯胺 |
95-53-4 |
2，4-Toluylendiamine |
2，4-二氨基甲苯 |
95-80-7 |
2，4，5-Trimethylaniline |
2，4，5-三甲基苯胺 |
137-17-7 |
o-Anisidine |
邻氨基苯甲醚 |
90-04-0 |
2，4-Xylidine |
2，4-二甲基苯胺 |
95-68-1 |
2，6-Xylidine |
2，6-二甲基苯胺 |
87-62-7 |
4-Aminoazobenzene |
4-氨基偶氮苯 |
60-09-3 |
EU Directive 2002/61/EC & 2003/3/EC accessories list the above 24 kinds of harmful aromatic amines. If the textile or leather is detected the above harmful aromatic amines content exceed 30 ppm, the textile will be forbidden in EU market. And along with the development of technology, once new harmful aromatic amines are confirmed by EU, the list will be updated.
The European Union (EU) and the state of California (Proposition 65) have banned a number of aromatic amines that have been classified as carcinogenic. These aromatic amines can be liberated when their parent azo dyes undergo cleavage due to a raised pH (e.g. from perspiration).
Some of the acid dyes used to color leather have been synthesized using one or more of the banned amines, and may be converted back to the free amines by perspiration.
We offer testing for the banned amines / azo dyes using the following test method:
INTERNATIONAL STANDARD ISO/DIS 17234 (IULTCS/IUC 20); Leather — Chemical tests — Determination of certain azo colourants in dyed leathers.
Azo dyes produce bright, high-intensity colors, have fair to good fastness properties, are economical to produce and account for more than half of all commercial dyes used.The carcinogenic aromatic amines used in producing the dyes may be released from a finished textile by perspiration or saliva, causing health risks from skin contact or ingestion. Azo dyes may contain any of more than 20 carcinogenic amines listed under California's Proposition 65 requiring the state to publish a list of chemicals known to cause cancer, birth defects or other reproductive harm. These carcinogens have been banned in China, Japan, India, Vietnam, and the European Union.
What are azo dyes?
Azo dyes are the major colourants used in the textile industry, allowing for a large spectrum of colours and increased colour fastness. They are a large group of synthetic organic dyes that contain Nitrogen as the azo group. Azo dyes are widely used in substrates such as textile fibres, leathers, plastics, papers, hair mineral oils, waxes, foodstuffs and cosmetics
Why carry out azo dyes testing?
Some Azo dyes are considered a risk to human health as they contain one or more nitrogen-nitrogen double bonds called azo groups; under reductive conditions these azo groups can be cleaved to form primary aromatic amines, which are known carcinogens.
PTS Testing Service any textile, leather, and synthetic materials and products for azo dyes to the following methods:
BS EN ISO 17234-1:2015 & BS EN ISO 17234-2:2011
BS EN ISO 14362-1:2017 & BS EN ISO 14362-3:2017
Why you need to test for azo dyes?
Textiles and leather products (that come into contact with the skin) imported into the EU are not permitted to contain azo dyes which release certain aromatic amines. This is laid down in Annex XVII of REACH. The detectable concentrations of any of the restricted amines should not exceed 30 ppm in the finished articles or in the dyed parts thereof.
What are Azo Dyes?
Azo dyes are the major colourants used in the textile industry, allowing for a large spectrum of colours and increased colour fastness. They are a large group of synthetic organic dyes that contain Nitrogen as the azo group.
What are the risks of Azo Dyes?
Azo dyes contain one or more nitrogen-nitrogen double bonds called azo groups, under reductive conditions these azo groups can be cleaved to form primary aromatic amines, which are known carcinogens.
Where are Azo Dyes found?
Azo dyes are part of our everyday life; they are used widely in substrates such as textile fibres, leathers, plastics, papers, hair mineral oils, waxes, foodstuffs and cosmetics.
What legislation relates to Azo dyes?
Textiles and leather products (that come into contact with the skin) imported into the EU are not allowed to contain azo dyes which release certain aromatic amines. This is laid down in Annex XVII of REACH.
Azo dyes are covered by the EU directive 2002/61/EC which contains a table list and consumer goods containing azo dyes that, by reductive cleavage of one or more azo groups may release one or more of the aromatic amines listed in the Table are forbidden.
Azo dyes are also covered in product specific regulations such as EN71 parts 9, 10 & 11 (Toy Safety Directive).
What are the limits for Azo Dyes?
