meaning of "free from"

Question

I did a test.
the test can be found below.
https://ieltsonlinetests.com/ielts-mock-test-2023-january-reading-practice-test-2?mode=practice_test&parts=2&duration=60
There is a question I am confused.

Those devices are designed to meet the safety criteria which should be free from ______

the answer is radiation.

but according to the relative context

Each has to meet stringent safeguards to make sure it doesn’t emit radiation that would interfere with other devices in the plane-standards that passengers’ personal electronic devices don’t necessarily meet.

Both pieces of information don't match each other, I suppose.
One is that it doesn’t emit radiation.
The other one is that it should be free from radiation.

To be free from radiation means not being affected by radiation, even if there is radiation.
it doesn't emit radiation means it will still be affected by radiation, it just won't emit radiation by itself.

am I right?

Answer 1

The quick answer is that "free from" variably means without, not containing, or similar. Something that is 'free from dairy' does not contain any dairy products; something that is 'free from contamination' is clean and has not been contaminated.

Your example is complicated by the fact that "radiation" is used in different ways. As a form of energy, something may emit radiation (ie it is the source of radiation), while other things may become contaminated by radiation (ie absorb the radiation).

The precise meaning of "free from contamination" would therefore rely on context. In your example, given the context, it means that the subject does not emit radiation. However, in another context it could mean that something has not been contaminated by it.