HQTS Quality Control

The Complete Guide to Azo Dyes and Azo Dyes Test

Azo dyes are a direct dye commonly used in the textile industry to colour fibres. They are also commonly found in paints, inks, and other products. They are potential carcinogens and have been banned in multiple countries worldwide, including Canada, Australia, New Zealand and Japan because they were associated with an increased risk of cancer.

Because of this, many products need to be tested to determine whether they contain any before they get imported to certain countries. In this article, you will learn everything you need to know about azo dyes and how to test for them.


What Is Azo Dyes?

Azo dyes are synthetic compounds characterized by one or many intramolecular NQN bonds. They are the primary type of dye used by the textile industry to colour the fibres directly, meaning it eliminates the need for mordants. But they´ve been banned from multiple countries because of their potential carcinogens.

Azo dyes can be used in a wide range of products, including:

  • Textile
  • Plastic
  • Paper
  • Leather
  • Wood


Why Are Azo Dyes Used in Textile Industry?

Azo dyes are used in the textile industry for different reasons. For example, they can be used to give a fabric a natural colour or to create new colours using different dyes.

Azo dyes are used in the textile industry because they allow the manufacturer to:

  • Have a wide range of colours and can be easily mixed to produce new colours
  • Have high resistance to fading.
  • Decreases the production time.
  • Relatively low-costs.


How Is Azo Dye Made?

Azo dyes tend to be produced in developing countries such as China, India and in Korea. They are used to dye many types of fibres – natural, artificial and synthetic – to colour. Diazonium salt is produced in the first step, and then it is reacted with aromatic compounds such as phenol in the second step. The different pathways produce different colour properties.

Why Are Azo Dyes Banned in Many Countries?

Azo dyes are used in many consumer goods as colourants, including apparel, leather, textiles, cosmetics and food. The use of Azo Dyes is banned in Canada, China, India, the United States and the European Union and many other countries because they pose a serious risk to human health and the environment. It has been shown that Azo dyes can be considered a risk to humans as they can contain nitrogen-nitrogen double bonds.

Why Use Azo Dyes Testing on Textiles and Leather?

In recent years, the use of Azo dyes has become regulated by chemical legislation, including REACH, China GB Standards, and California Proposition 65. Your responsibilities as an importer include complying with all regulations, including those concerning the product you are importing. There are many ways to do this, including carrying out azo dye tests.

What Is Azo Dyes Test?

Testing your product at an accredited laboratory is a great way to ensure that it is safe for use and meets legal requirements. The type of testing will depend on the material your product is made from. For example, leather products are often chemically tested for azo colourants in dyed leathers and 4-aminoazobenzene. Whilst textiles tests may include checking aromatic amines derived from azo colourants, the use of certain aromatic amines derived from azo colourants. Once completed, the laboratory will provide you with a azo free certificate, or a azo free test report.

Other Chemical Testing Items

Consumer goods are subject to various legal regulations and standards around the world. Other chemical items to pay attention to when importing include:

  • Allergenic disperse dyes
  • Carcinogenic dyes
  • Heavy metal
  • Formaldehydes
  • Phenols
  • PH
  • Pesticides
  • Phthalate
  • Flame retardants
  • PEoA/PFoS


Conclusion: The Complete Guide To AZO Dye Test

Azo dyes are a type of direct dye used in many industries to colour products, e.g. fibres in a garment. Research has shown that they’re potential carcinogens, which have been banned in many countries. Businesses importing goods that may contain azo dyes must test the item to ensure compliance with all regulations.

With over 25 years of experience in quality assurance, HQTS is ready to help your import and export business build a robust quality assurance plan. We have accredited laboratories and can help with azo dyes testing textile and leather products. Contact us today to find out how we can help you navigate your current quality control challenges.

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