Since the beginning of the 1930s research has been directed towards improving the effectiveness of water as a forest fire extinguishing agent. Throughout this time various chemical substances have been added to the water, and this is still the case today. Among these substances are the various types of long-term forest fire retardant, which maintain their ability to alter combustion when the water has been removed by evaporation. In order to provide an account of the current state of development of studies on long-term forest fire retardants, we carried out a bibliographic analysis with special attention to work done after 1976 on the different aspects that influence the final effectiveness of forest fire retardant: quality (programs and evaluation), effectiveness, application and environmental impact on streams and aquatic organisms, vegetation and humans. The scope of this work covers the wide subject of fire retardants and it introduces significant work related to all the aspects of fire retardant use.