Hydrazine is quite common and quite toxic, of the "seek medical attention immediately" variety. 1 ppm is a threshold for exposure for a few hours, satellites can launch with hundreds of pounds of the stuff.
A crashed satellite would not be safe to be around, you might get liver failure if you go poking around one and get a good ammonia-like whiff of hydrazine.
Hydrazine is certainly on some satellites, but by numbers of satellites launched and by mass of satellites launched hydrazine is not on a minority of them. Most satellites being launched by mass and number are now Starlink satellites which don't have hydrazine. Even then, the second largest category of satellites is smallsats and cubesats which often have no propulsion at all or use cold gas.
Hydrazine is quite common and quite toxic, of the "seek medical attention immediately" variety. 1 ppm is a threshold for exposure for a few hours, satellites can launch with hundreds of pounds of the stuff.
A crashed satellite would not be safe to be around, you might get liver failure if you go poking around one and get a good ammonia-like whiff of hydrazine.