Classification of radiation
According to whether the radiation particles can cause ionization of the propagation medium, the radiation is divided into two categories: ionizing radiation and non-ionizing radiation. In fact, electromagnetic radiation is just an electromagnetic wave. We often say that non-ionizing electromagnetic waves refer to electromagnetic waves in the radio frequency and microwave bands with a frequency of 30 to 3000 MHz. Because the energy of their photons is not enough to ionize neutral molecules and atoms, they are called non-ionizing.