Hazardous substances in textiles mainly come from two sources: one is the use of pesticides, fertilizers, herbicides, etc. during the planting process of textile raw materials to control pests and diseases. These toxic substances remain on textile products and clothing and can cause allergic reactions, respiratory diseases, or other poisoning reactions, and even induce cancer. The other source is the use of various chemicals such as dyes, oxidants, catalysts, flame retardants, whitening fluorescent agents, and resin finishing agents in textile processing, printing and dyeing, and finishing processes. These hazardous substances remain on textiles, causing them and clothing to be contaminated again. Since the German government promulgated the Order to Ban Azodyes on July 15, 1994, a total of 13 categories of about 300 chemicals have been banned or restricted in the fields of textiles and chemicals until now.
Below is a basic introduction to these 13 categories of chemicals.
Azo dyes are aromatic compounds containing one or more azo groups (-N=N-) and are an important structure in dyes. There are several thousand types of dyes with this structure. Studies have shown that certain aromatic amines have carcinogenic effects or suspected carcinogenic effects on humans or animals. Therefore, regulations in various countries only prohibit azo dyes that decompose to produce carcinogenic aromatic amines. Germany was the first country to promulgate an order banning the production and use of 20 carcinogenic aromatic amines represented by aniline, as well as dyes that can decompose into these aromatic amines. The regulation stipulates that importers are not allowed to import textiles that come into contact with humans and are processed with these dyes. Subsequently, this order has also been used by other EU countries. According to the data released by Germany's VCI (German Chemical Industry Association) in 1999 on banned dyes, there are 146 species of banned dyes, and the limit value of carcinogenic aromatic amines in textiles does not exceed 30 mg/kg, and the limit value of carcinogenic aromatic amines in dyes does not exceed 150 mg/kg.
Banned dyes may exist in dyed textiles or leather products.
Sensitizing dyes are allergenic and irritating to the skin. Some disperse dyes are considered to be prone to cause allergic reactions. If such dyes come into contact with skin for a long time, they can be harmful to the human body. Therefore, these dyes are restricted and banned in technical regulations and standards in some countries. At present, there are 20 controlled sensitizing dyes, and Oeko-tex has limited the use of these dyes, all of which are disperse dyes. Germany's Food and Consumer Goods Act limits the use of 6 disperse dyes that have been proven to cause allergic reactions.
Disperse dyes are mainly used for the printing and dyeing of polyester and its blended products, and sometimes also for the printing and dyeing of other synthetic fibers such as acetate and polyamide.
Carcinogenic dyes refer to dyes that can induce human cancer without undergoing chemical changes such as reduction. Currently, 9 types of dyes have been identified as carcinogenic, and Oeko-tex has restricted their use, including 3 direct dyes, 3 disperse dyes, 2 alkaline dyes, and 1 acidic dye.