Present in the dye industry and the textile industry, the role of human carcinogenic aromatic amines and the issue of banned azo dyes in-depth study and was recognized at the same time, the role of a carcinogenic aromatic amine composition of coatings made of organic pigments Printing paste Or paint coloring paste, whether banned azo dyes with the same hazard function, become another focus of discussion. In research and development of new pigments should not only consider the nature of its technology and applications, should also be investigated, concerned about its environmental, ecological and human impact. Today’s paint industry, should paint toxicity and ecological impact as an important research content.
And other similar chemicals, paint preparation and use of major consideration personal safety, air emissions, wastewater emissions and waste treatment related. Only pigment physical, chemical, toxicity and ecological nature of the research in detail in order to evaluate the toxicity and its particular color ecological harm to the environmental impact assessment. K. Henkel Corporation Hunger, etc. According to toxicity studies, comprehensive assessment of the various types of dyes and pigments on the environment and the potential impact on human health. Specific evaluation of pigment, “resume” should include the following: production (involving the starting material, impurities and by-products), paint application medium, the use of field paint, waste treatment.
General, insoluble organic pigments, so they are not in the most toxic. However, organic compound paint and other materials used, the typical organic pigment system in addition to pigments, other fractions such as adhesive, Solvent And various additives will also be on the ecology, the environment has important implications.
1 ecological impact As pigments in water, but also in other common solvents are difficult to dissolve, so the ecological impact of pigment is mainly responsible for manufacturers and processors.
This effect mainly from the exhaust gas and wastewater emissions.
Organic pigments will produce dust pollution in the air dust concentration in the organic pigments are not allowed more than 6mg/m3, production can be filtered out before discharge. In pigment production, grinding, dispersion and mixture should pay attention to the pollution of paint dust. To prevent the paint dust may come into contact, to be equipped with the necessary protective equipment.
Pigment in the production process waste water often contain carcinogenic substances (such as aromatic amines, nitrite), by filtration, sedimentation and other methods of purification. If necessary, can use biological treatment. The water should reach the row is not toxic to fish, at least there is no conclusive evidence of the harmful.
2 toxicity Toxicity involves many fields, mainly including the following: acute toxicity, skin and mucous membrane irritation, constant contact with use of sub-acute toxicity, allergy, mutagenicity, chronic toxicity and carcinogenicity.
2.1 Acute toxicity Acute toxicity is defined as a substance on humans or animals in the oral, skin or respiratory contact toxicity. Animal testing (such as mice, rabbits) can provide short-term exposure on human health preliminary information. Some of the 108 kinds of organic pigments on the toxicity of small mice, study shows that the LD50 values of these pigments than 5000mg/kg1 (weight). EU chemical regulations, only the oral LD50 value of less than 2000mg/kg was considered poisonous. Salt LD50 values compared to about 3000mg/kg, so the organic pigment was in fact not characteristic of acute toxicity. Usually paint a general discharge by gastrointestinal, and not excreted in urine.
2.2 skin and mucous membrane irritation
Table 1 summarizes the product and the paint on the mucosa of rabbits, their impact, including the role of additives. Research shows that color has a high LD50 values, only a very small number of pigments can produce skin and mucosal stimulation.