The explosion resulting from the mere mixing in an inert atmosphere of ternary systems using H2O2and N2H4(or MMH or UDMH) has been investigated. The composition ranges leading either to ignilion or to detonation have been experimentally determined. A correlation allowed the authors lo propose an isoenthalpy line which is used as the envelope for the self-detonation range. Reaclional processes are considered Intermediate chemical species are different for ignition and detonation. Additives may help in one case or the other.