They won't understand, they'll just think they do. Just as if you talked about the dangers of "chemicals" and how dihydrogen monoxide kills thousands of people a year.

I've seen countless disagreements on numerous topics caused by people thinking they both have the same definition of a term and even more instances of confusion because the intuitive implicit definition that came from the example usages they'd seen of a term was a non-representative subset of the things matched by the explicit definition.

Nuance and clarity of language matters, otherwise you'll ban "chemicals" and discover you actually have no sane definition of it and are inflicting a lot of unnecessary suffering.