Cadmium pigments are lightfast, stable at high temperatures, intensely colored and migration-resistant, but have only limited weather resistance. Their specific gravity is between 4.2 and 5.6 g cm-3 and their average particle size between 0.2 and 0.5 pm. They have very good hiding power and still find application in the coloring of engineering plastics and ceramics [3.100, 3.101]. They are practically insoluble in water and alkaline solutions, but are attacked and decomposed by acids. Care must be taken during application of these pigments, especially the red cadmium sulfoselenides, because of their sensitivity to friction. Excessive shear forces can cause a color change in the pigments.
The toxicological properties, identification requirements and application restrictions are described in detail in Ref. [3.102].
3.2.2