AbstractChemical structures limited to phosphines and their derivatives, including phosphine oxides, phosphonium salts and halogen‐phosphorus compounds useful for fireproofing are discussed. In addition to these P‐C bond containing compounds, structures containing P‐O‐C bonds are mentioned only if they are directly formed from halophosphorus substances. The general approaches to fireproofing are described. They include physical changes, unreactive additives, reactive comonomers, substitution of other functional groups and addition to a preformed polymer. Much of the literature is reviewed and the commercial importance of certain methods for both cloth and plastics are in