An inorganic compound with the formula Cl03F, that was tried as a liquid-fuel rocket oxidizer in the 1960's. Although it is a gas at room temperature, its critical temperature is well above room temperature; therefore, it can be liquefied by pressure alone. Unlike chlorine pentafluoride or bromine pentafluoride, perchloryl fluoride does not corrode tanks. However, it is not nearly as powerful as those two oxidizers in terms of specific impulse. It is made from sodium perchlorate and hydrogen fluoride.