Hydroquinone has a variety of uses principally associated with its action as a reducing agent which is soluble in water. It is a major component in most photographic developers for film and paper, and is used as a topical application in skin whitening to reduce the color of skin. In this book, the authors present current research in the production, uses and health effects of hydroquinone. Topics discussed include the cellular effects of hydroquinone; the involvement of cigarette smoke-related hydroquinone in the pathogenesis of age-related macular degeneration; hydroquinone solubility and separation processes; the transport and transfer processes of poly(o-aminophenol)film electrodes in the presence of the hydroquinone/p-benzoquinone redox couple and the detection of thiols using hydroquinone on gold surfaces.