AZO dyes Testing
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:
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English Name
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Chinese Name
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CAS No.
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4-Aninobiphenyl
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4-氨基聯苯
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92-67-1
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Benzidine
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聯苯胺
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92-87-5
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|
4-Chloro-o-toluidine
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4-氯-鄰甲基胺
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95-69-2
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|
2-Naphthylamine
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2-萘胺
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91-59-8
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o-Aminoazotoluene
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鄰氨基偶氮甲苯
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97-56-3
|
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2-Amino-4-nitrotoluene
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2-氨基-4-硝基甲苯
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99-55-8
|
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p-Chloroaniline
|
對氯苯胺
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106-47-8
|
|
2，4-Diaminoanisole
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2，4-二氨基苯甲醚
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615-05-4
|
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4，4’-Diaminobiphenylmethane
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4，4’-二氨基二苯甲烷
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101-77-9
|
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3，3’-Dichlorobenzidine
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3，3’-二氯聯苯胺
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91-94-1
|
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3，3’-Dmethoxybenzidine
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3，3’-二甲氧基聯苯胺
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119-90-4
|
|
3，3’-Dimethylbenzidine
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3，3’-二甲基聯苯胺
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119-93-7
|
|
3，3’-Dimethyl-4，4- diaminobiphenylmethane
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3，3’-二甲基-4，4-二氨基二苯甲烷
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838-88-0
|
|
p-Cresidine
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2-甲氧基-5-甲基苯胺
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120-71-8
|
|
4，4’-Methylene-bis-（2-chloroaniline）
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4，4’-亞甲基-二-（2-氯苯胺）
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101-214-4
|
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4，4’-Oxydianiline
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4，4’-二氨基聯苯醚
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101-80-4
|
|
4，4’-Thiodianiline
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4，4’-二氨基二苯硫醚
|
139-65-1
|
|
o-Toluidine
|
鄰甲基苯胺
|
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
|
鄰氨基苯甲醚
|
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
|
U 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.
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