Toxicity properties colorants

In the past, juglone had been used to dye wool and cotton a yellowish brown. Although it no longer has any commercial value as a dye, it is a fungicide and as such finds use in the treatment of skin diseases. Its toxic properties have been made use of in catching fish. Juglone has been used to detect very small amounts of nickel salts since it gives a deep violet color with such salts. 

Properties Colored crystals. Mp 32.1C, bp 220C. Hazard Toxic by ingestion and inhalation. 

A survey of acute oral toxicity, as measured by the 50% lethal dose (LD j) test, demonstrated that of4461 colorants tested, only 44 had an LD-,j< 250 mg kg and that 3669 exhibited practically no acute toxicity (LD > 5 g kg ). The rest fell somewhere between these two levels. The evaluation of these colorants by chemical classification revealed that the most toxic ones were found among the diazo (mostly benzidine derivatives) and the cationic dyes. It is widely known that some general cationic compounds have toxic properties. Pigments and vat dyes by comparison were discovered to have extremely low acute toxicity - presumably due to their insolubility/very low solubility in water and in lipophilic systems. 

Properties Color or wh. ctyst. powd. luminous when heated insol. in water sol. in ammonium salts, acids pract. insol. in water m.w. 78.08 dens. 3.180 m.p. 1360 C b.p. 2500 C Toxicology LD50 (oral, rat) 4250 mg/kg, (IP, mouse) 2638 mg/kg mildly toxic by ing. mod. toxic by IP route irritant mutagen experimental teratogen TSCA listed... 

The performance of stabilizers is not only determined by its effectiveness to protect the polymer against degradation, but also by its physical properties, color, discoloration, interactions with ofeer additives, chemical resistance, dosability, toxicity, food approval, and price. 

Moreover, multivariate optimization, the simultaneous optimization of several properties, will increasingly come into focus. A drug should have high selectivity in binding to different receptors and minimal toxicity, good solubility and penetration, and so on. A hair color should have a brilliant shine, be absorbed well, not be washed out, not damage the hair, not be toxic, and be stable under sunlight, etc. 

Pigments and Extenders. Pigments are selected for use in house paints based on thek appearance and performance quaUties. Appearance includes color and opacifying abiUty. Performance quaUties include ultraviolet light resistance, fade resistance, exterior weatherabiUty, chemical resistance, as well as particle size and shape. Toxicity profiles and safety and health related properties are also important criteria in pigment selection. 

---