Pure hydrazine maybe, as that’s not soon that common. But the derivatives MMH and
UDMH (which are both equally devastating to humans/the environment) are certainly used in the atmosphere, even by western nations. It’s common as an orbit raising fuel.
IIRC Hydrazine is generally only used, or was used as the RCS thrust fuel for the Apollo program. You know, outside of the Earth’s atmosphere.
Pure hydrazine maybe, as that’s not soon that common. But the derivatives MMH and UDMH (which are both equally devastating to humans/the environment) are certainly used in the atmosphere, even by western nations. It’s common as an orbit raising fuel.