Skin is an organ with very important funcions for the living.It is used as an industry raw material at the end of the life of animals.As such,it is treated as raw skin in the industry.Skin is an organic stucture whose main ingredients are water,protein,fat and minerals.Morphologically it has the characteristics of a weaving made of protein fibers,observed at a micro level.The fibrous structure is mostly collagen ,the main protein of skin.Raw skins can be transformed into processed leather after a series of chemical,physical and mechanical processes.With these processes,natural fibrous structural integrity of the skin fixed and its protection against biological,physical,chemical and other environmental effects is secured.That is why processed is defined as "tanned collagen "in scientific circles.Leather chemicals are the chemical materials used in transforming raw skin into processed leather.In order to transform a biological structure into an industrial product,a series of chemical reactions are necessary ensure that the chemical structure is made unbreakable.                                   There are specialized facilities in the chemical sector that cooperate with leather enterprises and work on identifying,developing,producing and applying these reactions and chemicals.