The GeNO nitric oxide delivery technology works by passing pre-diluted NO₂ gas in O₂ or air through a small specially designed chemical reactor operating at ambient temperature called a cartridge.  The cartridge, which is the heart of the system, is used to remove an oxygen atom from NO₂ and generate pure nitric oxide in O₂ or air at the determined therapeutic dose. The purity of the nitric oxide gas in O₂ has been tested using a variety of instrumentation techniques. The NO₂ level at the exit of the cartridge has been shown to be lower than what is typically present in ambient air.

Paradoxically, although GeNO's nitric oxide delivery systems start with NO₂, it delivers nitric oxide to the patient essentially free of the NO₂ impurity.