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.