I said "poison" to refer to something that is sold for the purpose of being devastating to many forms of biological life. I and many very smart and well-educated people I know prefer to avoid exposing ourselves to industrial poisons if we can avoid it, even if they target different species.

Speaking of LD50 values: I know some people who ingest borax as a mineral supplement, and its LD50 is higher than table salt, roughly double if I recall correctly. I bet I can't get you to try it as a dietary supplement! The point is that there is more to consider than that one specific measurement.