Phozol is an unstable phazon-fuel gel compound sometimes used in starships such as the Tempest Gunship. The instability of this compound has lead some to weaponize it in chemical sprayers. Oddly enough, it can also be used for pest control (provided that the pest is not mutated by phazon).
The fuel efficiency in a starship engine, is around 1.5 parsecs/liter. When used in a Particle Reactor, efficiency is around 100 Giga Joules per liter. While the efficiency of this compound is very desirable, the instability is not.
The FEIS has a strict monopoly on this substance, with only a select few planets having fuel gel and phazon resources adequate enough to produce the substance naturally.