Colourants in cosmetics: Fact Sheet III
Both organic and inorganic colourants may contain heavy metals as impurity. Colourants are used to impart colour to almost all cosmetic products. Primarily they are of two types: Organic colourants such as dyes and organic pigments which are fairly soluble and lakes which are fairly insoluble. Inorganic colourants lack a carbon molecule. They are composed of fairly insoluble metallic compounds which are either derived from natural sources or are synthesised, like iron oxide and titanium dioxide.