The question asks for how to destroy heroin. It doesn't ask for ways to nullify the effects after consumption, or even mentioned human (or any other) biological behavior in the slightest. I don't see how this question would fit this custom close reason. (What to add to heroin to make it harmless?)
I am not arguing here for it to be reopened, I am simply asking, how this particular close reason makes sense.
For me, it also doesn't make much sense to put this question on hold in the first place. However, I could understand that it lacks prior research and as such may have a difficult standing.
I do think that such safety concerns should be addressed, as I have seen videos of police officers destroying marijuana by burning it, intoxicating all surrounded.