There are many types of electromagnetic radiation: gamma rays, x-rays, ultraviolet light, visible light, infrared light, radio waves, etc. Each type of radiation has a different effect on the body.
Researchers study these effects and establish exposure limits on the basis thereof for the different types of electromagnetic radiation. An exposure limit indicates what the maximum radiation intensity can be to prevent harmful effects on the health.
Exposure limits are not yet legal standards because these are not specific enough and are not binding. In order to be specific, the exposure limits must be converted to actual practical situations (for products such as a mobile telephone or for installations such as transmission towers). The limits must be adopted in the regulation to be binding. You can read about this in the section “Standardisation of electromagnetic radiation”.