E: Article containing a secondary detonating explosive substance without means of initiation, with a propelling charge ( other than one containing flammable liquid, gel or hypergolic liquid ) ( 1. 1E, 1. 2E, 1. 4E ).

F containing a secondary detonating explosive substance with its means of initiation, with a propelling charge ( other than one containing flammable liquid, gel or hypergolic liquid ) or without a propelling charge ( 1. 1F, 1. 2F, 1. 3F, 1. 4F ).

G: Pyrotechnic substance or article containing a pyrotechnic substance, or article containing both an explosive substance and an illuminating, incendiary, tear-producing or smoke-producing substance ( other than a water-activated article or one containing white phosphorus, phosphide or flammable liquid or gel or hypergolic liquid ) ( 1. 1G, 1. 2G, 1. 3G, 1. 4G ).

L Explosive substance or article containing an explosive substance and presenting a special risk ( e. g., due to water-activation or presence of hypergolic liquids, phosphides, or pyrophoric substances ) needing isolation of each type ( 1. 1L, 1. 2L, 1. 3L ).

Originally developed in the late 1950s by Aerojet General Corporation as a storable, high-energy, hypergolic fuel for the Titan II ICBM rocket engines, Aerozine continues in wide use as a rocket fuel, typically with dinitrogen tetroxide as the oxidizer, with which it is hypergolic ( ignites on contact ).

A potentially novel hypergolic alternative has been developed based on tertiary amine azides-called CINCH ( Competitive Impulse Non-Carcinogenic Hypergol ).

The CPM is designed to maximize simplicity-it uses no turbopumps and no ignition system ( because of the hypergolic propellants ).