IRFNA (Inhibited Red Fuming Nitric Acid) (HNO₃ + ~13% N₂O₄ + ~0.6% HF) is a storable oxidizer propellant used as a oxidizer. Storable for months with proper containment. Typical ISP: 255–275 s (with UDMH) seconds.
Inhibited Red Fuming Nitric Acid is a storable oxidizer consisting of concentrated nitric acid with dissolved nitrogen dioxide and a small amount of corrosion inhibitor (typically HF). It is hypergolic with amine-based fuels and was widely used in early ballistic missiles. IRFNA’s storability made it attractive for military applications despite its corrosive and toxic nature.
Used in Nike Ajax, Corporal, and early tactical missiles. Largely replaced by NTO for most applications due to corrosion issues.
Storable, hypergolic, high density, relatively inexpensive
Extremely corrosive, toxic, attacks most metals and organics, lower Isp than NTO
