Characteristics of nitrogen oxide molecules
NOx (Nitrogen oxides)

The term NO_x is the generic term for a series of compounds containing nitrogen and oxygen at different oxidation stages. These include nitrous oxide N₂O, nitric oxide NO, nitrogen dioxide NO₂, nitrogen tetraoxide N₂O₄ and nitrogen trioxide N₂O₃ (sometimes also N₂O₅), but also, in the presence of water vapor, the nitrous and nitric acids HNO₂ and HNO₃ respectively.

The N₂O (nitrous oxide) file [G 1 830] des Techniques de l'Ingénieur clearly presents the more specific issue...