Interpretation Of "Specific Azo Dyes" And Related Standards

In recent years, the issue of product safety has attracted more and more attention from consumers.

Textile products will be applied to various chemicals in dyeing and finishing processes. These chemicals may contain more or less harmful substances to human body. The reduction and cracking of harmful azo dyes will become a problem. Because such dyes are absorbed by human body, the reductase in the human body will cause the dye to reduce and cleavage. In addition, in the long-term contact with human body, the dye may be absorbed by the skin and spread in the human body, and the carcinogenic aromatic amines can be decomposed by reducing reaction, and after activation, the human body's DNA structure will be changed, causing human diseases and inducing cancer.

Recently, China

At present, the ban on aromatic amines has become a basic environmental standard. The Japanese industry self-discipline standard involves 22 kinds of aromatic amine substances.

As early as 1992, the German government promulgated the "food and daily consumer goods law". The decree clearly pointed out that azo dyes, which cracked and released carcinogenic amines under certain conditions, were banned in China, and the national textile product basic safety technical specification GB18401-2003 was introduced in 2003, and the textile products sold in China must be implemented in January 1, 2005.

China's "basic safety technical specification for national textile products" explicitly prohibits 23 azo dyes to avoid potential safety risks, guard against excessive azo dyes and protect people's health and safety.

Matters needing attention in the detection of banned azo dyes in textiles

The standard of test method gb/t17592-2006, the determination of prohibited azo dyes in textiles, is vague in terms of operation. The same inspectors may differ in actual operation due to their different understanding of standards, which will affect the reliability of measurement.

(1). Comparison of product scope applicable to new and old standards.

The standard gb/t17592-1998 is applicable to textile products that are suitable for cotton, wool, linen, silk and viscose fiber.

In fact, in addition to natural fiber and viscose fiber, there are a large number of synthetic fiber products.

Due to the narrow application scope of the original standard, there is no basis for detecting azo dye content of these products.

Therefore, gb/t17592-2006 has clearly pointed out in its application scope "textile products suitable for dyeing and finishing."

Textile products processed by printing and dyeing are products that are dyed or printed with various coloring agents, including dyes (dyes), paints or pigments (pigments).

(two) sampling

For the detection of banned azo dyes, different sampling methods may lead to different test results, resulting in missed detection or misjudgement. Therefore, it is necessary to clarify the sampling method.

There is no special requirement for sampling of products of single color, even mixed colors or similar effects.

For textile products consisting of different components of fibers or colors, individual components are detected separately.

Products with flower pattern (including printing and dyed fabrics) do not detect any color block as an independent component in principle. They are usually sampled according to the following methods:

(1) for regular flower pattern, take at least one circular pattern or several circular patterns, cut and mix.

(2) for larger or irregular patterns, sampling as much as possible according to the proportion of the hue of the main body.

(3) for local printing, independent printing and dispersed pattern of white land, sampling should include the color of the main body in the pattern. When the pattern is very small, it is not suitable to cut it from multiple samples and form a sample.

If these local flowers or disperse colors are different, it is advisable to sample and test separately.

If it is only a test of internal production control or quality analysis, it is another matter, and it can be detected separately by taking one pattern or one color.

In principle, each flower is sampled separately.

If there are no special requirements and samples are more than 3 colors, a suitable amount of samples can be mixed before sampling.

Because the detection limit of gb/t17592-2006 is 5ppm, when each flower color is 3, each flower can be sampled separately and mixed with 0.33g as a sample test.

In the case of 2 colors, each flower sample can be sampled separately and mixed with 0.5g as a sample test.