I don’t know about ”most people in the workforce.” I’m in my mid-30s, and not only do I remember it once or twice from my childhood, I also encountered it once in 2013 (at a brewpub somewhere in New York). You’re right, though, that it becomes less of a thing with each passing year.

I’m neither a writer nor a scientist, but there’s a copy of this on my bookshelf and I wish I could lend it to you: Deadly Doses: The Writer’s Guide to Poisons