How do they calculate the security of e\m fields when they do ala AppleWatch?

Question

Electronics

Actually a subject.
After all, there are standards for radiation, somehow such devices (smart watches, the same phones, bluetooth headphones, home routers) are certified for radiation, I wonder how everything is calculated there, based on what requirements.

Answer 1

They pay money for examination in the laboratory.
The relevant law is opened in the laboratory - SanPiN 2.1.2.1002-00 6.4. They look at the norms of certain field parameters (strength, etc.). And they measure it from a prototype using a verified measuring instrument with an established measurement technique. And all this is written in the law.