Use of Radiation sources
Radiation in the electromagnetic spectrum with energy of less than 12 eV (typical of the range of the spectrum between UV radiation and X-rays) is non-ionising radiation, in that it does not have sufficient energy to ionise atoms (‘break’ the bond between the nucleus and electrons) in the human body.
Ionising radiation includes X-rays (with a frequency in the range of: 1016 Hz -1019 Hz) and gamma rays (with a frequency of >1019 Hz).