Why RF is non-ionizing radiation: its photons lack the energy to break chemical bonds or knock electrons loose, so the main established biological effect is heating. RF fields make water molecules and ions in tissue oscillate, and that friction raises tissue temperature, which is why FCC exposure limits are based on specific absorption rate (SAR) and power density. Poorly cooled tissue such as the eyes and testes is considered especially susceptible to RF heating.
Watch out Radiation poisoning and depressed blood counts come from ionizing radiation such as X-rays, gamma rays and nuclear particles, which RF is not.
RF is non-ionizing: think microwave oven, not X-ray. It cooks, it does not ionize.