Chemical reactions which can, on demand, be switched on and off are valuable for industrial applications. In order to make the best use ofthese reactions, it is essential to have them readily available for a research chemist. The chemical literature, in general, has not yet identified or grouped such reactions. However, their existence is relatively abundant. This book is meant as a survey ofthose reactions which have potential utility in industrially useful processes. These reactions are grouped under the title ofchemical release reactions which can be triggered by heat, light, electric current, etc., to release a specific compound from, or change in the physical or chemical properties of, a unimolecular reactant. The book is divided into chapters covering ways to trigger the release of certain chemicals. Each chapter is further divided into sections, each beginning with a brief introduction ofanalogies ofthe discussed reactions and of how they were used in reported industrial processes. This survey is not meant to be absolute or exhaustive but rather to be directive, to be as complete as possible, and to provide food for further thought.