Читать книгу Sustainable Practices in the Textile Industry - Группа авторов - Страница 17

Synthetic dyes are made by organic molecules. They are derived from coal tar hence also known as coal tar dyes. William H Perkin synthesized “Mauve” the first synthetic dye in 1856 in the United Kingdom. Then, a significant number of dyes were discovered and industries quickly adopted them to grow, mainly in the United Kingdom, Switzerland and Germany [16].

The Sudan I (Solvent Yellow 14) is one of the members of azo-dyes widely used in textile industry [17]. It is enzymatically transformed, through the action of the intestinal flora, into carcinogenic aromatic amines, when present in the bodies of animals or humans [18]. In the case of azo-dyes, especially, carcinogenicity can be produced by both the dye itself and its own converted compounds [19]. The study of National Toxicology Program confirmed the neoplastic liver nodules in rats by the presence of Sudan I dye [20]. The Basic Red 9 dye, used in the textile, leather, paper and ink industries [21], develops carcinogenic potential in humans [22], and high toxicity to environment [23]. Under anaerobic conditions, it breaks down into carcinogenic aromatic amines, and when disposed in water bodies can cause allergic dermatitis, skin irritation, and cancer [24]. According to the in vivo tests on rats, it causes local sarcomas and tumors in the liver, bladder [25], mammary glands and hematopoietic system [26].

The Crystal Violet dye, shows an intense color [27], and is a member of the cationic triphenyl methane group, and is responsible for mitotic poisoning and abnormal accumulation of metaphases [28] as well as the in vitro clastogenic effects observed in Chinese hamster ovules [29], which induce chromosomal damage too [30]. According to Bharagava et al., this powerful carcinogenic agent promotes fish tumors [28, 31] and hepatocarcinoma, reticular cell sarcoma in various organs, such as the vagina, uterus, ovary and bladder [32] as well as hardened gland adenoma and ovarian atrophy in rats. In humans, it is capable of generating respiratory and renal failure, chemical cystitis, skin irritation and digestive tract disorder [28].

Advantages/Merits of Synthetic dyes

1 Easy preparation.

2 Available in large numbers and quantities.

3 Quality of fast colors

4 Cost effective.

Disadvantages/Demerits of Synthetic dyes

1 Production on high temperature

2 Carcinogenic

3 Hazardous to human health.

4 Problem of environmental pollution.