The company I'm working at is a subsidiary of Hartz, one which makes feed and pet treats, as well as milling and packaging various kinds of wood-shaving beddings. This includes cedar, which isn't healthy for small animals, but also aspen, which is.

Thankfully, no other poisons are (to my knowledge) part of the products made there.

Even so, "Suffer not a poisoner to live". I'm conflicted.