Melanocytes are dendritic cells derived from the neural crest that are responsible for the synthe- sis of melanin in a specialized organelle called the melanosome. These organelles are transferred to keratinocytes, where they are aggregated and destroyed by phagolysosomes in Caucasians but not in Negroids or Australoids. A number of morphologic differences exist between the races both in the production and lysis of melanosomes and in the degree and type of melanization. The role, if any, that pigmentation plays in modifying chemical damage in the skin is still contentious. although melanin has a major role in protection against ultraviolet (UV) radiation. Melanin is both an oxygen scavenger and a sunscreen. It may also function to remove the mutagenic and carcinogenic toxic oxygen from the surrounding keratinocytes and Langerhans cells." These substances appear to be less relevant in chemical sensitivity. since no matter the amount of pigment. they appear to afford no advantage in the retardation, development, or propagation of chemical sensitivity separated from and attached to the dermis by a basal lamina.