Radiation was a byproduct of many natural and artificial substances. Deadly items that were of this nature were deemed radioactive. Radiation encompassed the entire electromagnetic spectrum, including gamma rays, ultraviolet, infrared, and microwave radiation. It was categorized into five phases, with Phase 5 being the deadliest.
Sources of radiation
Natural radiation of all kinds was emitted from stars and interstellar gases, as well as certain materials and elements such as uranium, and even volcanic lava on various planets such as Qat Chrystac.
Radiation would also be emitted as propulsion from certain types of spacecraft as ion particles in twin ion engines, and from certain atmospheric speeders like the Koro-2 all-environment exodrive airspeeder.
The Galactic Empire created the elite Radiation zone assault trooper, or Radtrooper, to work in environments saturated in radioactivity. A radiation bomb was also used by Commander Thrawn in 27 BBY to eradicate life aboard the Outbound Flight.
Radiation detectors were worn around 4 ABY to alert the wearer while in the presence of high levels of radiation. The bounty hunter and slaver Bossk wore a radiation detector on his hip while he inspected Boba Fett's ship Slave I for hidden traps.[source?]